Canon Discrepancies

How Long Did Sam Spend at Stanford?

One of the most frequently debated potential canon discrepancies. Here are the facts:

• In the 1.01 Pilot, Sam is about to be interviewed for law school, which could work on the assumption that he's just about to finish a bachelor degree (4 years). Dean also says that he hasn't spoken to Sam in "nearly two years."
• In 1.03 Dead in the Water, Dean tells Sam that he spent "Every day for two years with Dad, while you were going to pep rallies."
• In 1.07 Hook Man, Dean says "So this is how you spent four good years of your life, huh?" when they are researching in the library.
• The original promo dates Mary's death to September 13, 1985, consistent with Sam being twenty and having been at Stanford for two years but out of step with everything else in the series.

Eric Kripke acknowledged during a panel at the 2006 William S. Paley Television Festival that they made a mistake in the script -- initially Sam was meant to be 20, then they aged him up to 22, but neglected to change Dean's line from "two years" to "four years." Therefore, it may have been the creators' intention that Sam has been at college for four years.

Regardless of intentions, however, there is a school of thought that disallows such retconning external to the text itself. That is to say, once the episode has been aired, whatever has occurred in it becomes part of the canon, no matter how much the production crew say "We didn't mean it that way" -- it's essentially out of their hands. With this line of reasoning, it's possible to read this particular issue as not contradictory at all -- Sam has spent four years at college, but it has been only two years since he's had contact with Dean.

Another suggestion is that it was not two or four but three years. This theory is based on the suggestion that if four years had passed since Sam left for Stanford, he would have already graduated and been in law school by the time of the pilot (which he is not). With this line of reasoning, Sam could not logically have been away for four years. This theory also takes into account the timeline of the pilot -- set at Halloween, Sam would only have been two months into his fourth year of college. This would mean that he has been at Stanford for three years and two months.

There is also the possibility that Sam's first two years in college were as a high school student participating in a dual-enrollment program. This would mean that Sam earned college credits in his final two years of high school and was, in fact, a senior in college by the time of the pilot.

Ruby's knife

The affect the demon-killing knife has had on higher ranked demons has wildly varied. The first demon, Lilith showed a level of fear being around the knife, while Alastair has survived being stabbed twice with the knife in non-fatal spots such as the left shoulder, though he still winced in pain. While a Prince of Hell like Ramiel was shown to be practically immune to the knife after being stabbed by Sam in the side, and shrugged it off as if it were nothing, despite arguably being of lower rank than Lilith and Alastair. Abaddon also has survived being stabbed in the back, having showed similar pain reactions as Alastair did when he was stabbed.

Dean's Police Records

Both of the police records for Dean we have seen onscreen (in 1.15 The Benders and 2.08 Crossroad Blues) have been inaccurate:

• In his "The Benders" record, Dean is listed as being 6'4", the same height as in Sam's police record, though Dean is clearly several inches shorter than his brother.
• In his "Crossroad Blues" record, Dean's height is correct (6'1"), but his eye color is listed as brown (whereas in the "The Benders" record it was correctly described as green).

Hunter's Blog

The Hunter's Blog on the official website appeared before season two started airing, and the content on it changed as time went on.

You can read a transcript of Jo's Journal on her character page. You can see the different versions of the journal there. In Jo's Journal she refers to Ash as "Miles." This was Ash's name in earlier scripts for 2.02 Everybody Loves a Clown.

Tie-ins: Origins, Website & TV

There are some inconsistencies between the information given in Origins, The Journal, the Hunter's Blog and the episodes themselves. For example:

• The Journal says that after Mary's death, John stays with Mike & Kate Guenther. However, in Supernatural: Origins #1, John and the boys are staying with Mary's best friend, Julie.
• In The Journal, John meets Missouri when he decides to visit psychics. In Supernatural: Origins, Missouri comes to John, seeking him out in a bar where he's hustling pool.

The pre-series section on the timeline page deals with these inconsistencies by documenting all canon (contradictory or not) and color-coding them according to their source, to reduce confusion.

The Origin of the Impala Controversy

In the teaser for 1.01 Pilot, John, Sam and Dean are clearly seen huddled together on the hood of the Impala as their house burns. In the Origins comics, Peter Johnson had John acquiring the Impala after Mary's death. Following a Q&A session with Cynthia Boris on Jack Myer's MediaVillage site, Peter Johnson returned with the following response (Source):

"I've given a huge amount of thought to the Impala issue and have arrived at a conclusion.

As you may know from previous posts, I felt early on that there would be creative and character-driven value to seeing John get the Impala during his journey in the aftermath of Mary's death. It was a decision, and Kripke and I talked about it. However, I'm in violent agreement with many of your comments that the car is the third character in the show, and that it represents a sanctuary for this family following the death of Mary. I like it as the constant that remains after her death - as Mousitsa (Anna) puts it: 'baby' was there to support her three men after the fire.

These comments have made profound impact, and I agree wholeheartedly with the thematics they represent for the SN universe - for both TV and comics. So, despite the fact that #1 and #2 have both been published, I am going to propose making adjustments to revert to John already having the Impala from the get-go when the issues are collected into the trade paperback. I would like to restore this notion to the comics.

I believe in my heart and gut that it would be the correct version, not just to match the shot of John and the boys of the hood of the Impala in the pilot teaser, but much more importantly, for what the car represents in the continuity of the family -- before and after Mary's death. I'll be talking to DC about this on Monday."

In December 2007, Peter Johnson confirmed that the history of the Impala would be changed to the canon established in the pilot, with the release of the trade paperback of Supernatural: Origins in April 2008 (Source).

It was in 4.03 In the Beginning and later 5.22 Swan Song that the provenance of the Impala was clearly established.

Demons and the Master Plan

Prior actions and statements of several demons ultimately revealed to be involved in the plan to free Lucifer from the Cage have caused discrepancies:

• Azazel's original plan stated to Sam in 2.21 All Hell Breaks Loose: Part One makes mention of "other generations" of Special Children and in 1.21 Salvation he attempts to feed demon blood to the infant, Rose Holt, making it appear that he had other intentions for them than just narrowing down the psychics of Sam's age to one person who would become the vessel for Lucifer. It is unclear why he would go to the trouble of making other generations when, as Azazel himself reveals in the same episode, he only needed the one winner of Sam's generation. Azazel's mention of "other generations" of psychic kids brings up another inconsistency, in 4.22 Lucifer Rising, Azazel only gets instructions to find a "special child" in 1972, a year before he makes his deal with Mary. If Azazel made similar 10 year deals with other women as with Mary, Sam and his generation would be the only psychic children.

• Lilith's plan for season three and most of season four seem to contradict her and Azazel's endgame to use Sam to free Lucifer. In season three it is her intent to kill Sam, going so far as to put out hits as well as personally attempting to kill him, and is horrified when he survives. In season four she decides to make a deal with Sam to stop breaking the seals because she fears for her life. But she had to have known she was the final seal when she began her plan with Ruby to train Sam in honing his demon powers, and Ruby even claimed that everything Lilith did was meant to get Sam to break the last seal and become Lucifer's vessel.

• Ruby tries to convince Sam to use his powers to kill Lilith in 3.16 No Rest for the Wicked to save Dean, despite the fact that the first seal had not yet been broken by Dean -- who needed to go to Hell to do so, which Lilith's death would prevent -- and Lilith's death therefore wouldn't free Lucifer. She also indicates that Sam would be able to kill Lilith with only about a day's training, even though in season four it would ultimately take months for him to reach a level where he could kill Lilith even with training, a great deal of demon blood, and Lilith not fighting back. Ruby was risking Sam's trust by making claims she couldn't possibly deliver on, given revelations in season four about what would've needed to happen for her plan to work.

Sam, Demon Blood and Lucifer's Vessel

In 5.21 Two Minutes to Midnight, Castiel tells Sam that for him to take in Lucifer, he would have to consume more demon blood than he has ever drunk before. Telling him it will strengthen the vessel to keep it from exploding, explaining how Nick is only being held together by Lucifer's consumption of gallons of demon blood. However, it is not explained why, that if Sam is Lucifer's true and destined vessel, he would have to drink demon blood, whereas Dean, being Michael's true vessel needs no preparation.

The Missing Year Between Seasons 5 & 6 and 7 & 8.

The first five seasons of the show take place in the current time. For example, season one aired from 2005 to 2006, and the events covered in that season span 2005 - 2006. This remains consistent through season five, which concludes around May 2010. This is confirmed by a calendar seen on the wall in 5.21 Two Minutes to Midnight. Then, as stated in 6.01 Exile on Main St., a time jump of "about a year" occurs between season five and season six. The title card at the beginning of the season premiere reads "ONE YEAR AGO" before the events of 5.22 Swan Song are recapped, and then "NOW" before Dean is shown in bed with Lisa. Then, in 6.12 Like a Virgin, Dean tells a newly awakened Sam that he's been gone for about a year and a half. That would mean that the date halfway through season six should be sometime around November 2011.

The writers/crew at Supernatural decided to continue their tradition of dating things for the estimated release time of the episode, ignoring the fact that, because Dean lived with Lisa for a whole year between the end of season five and the beginning of season six, season six should start in 2011, not 2010.

According to 1st AD Kevin Parks:

"They decided to do 'soap opera time,' because they didn't want to have to push the year forward for the rest of the show's run. So, just like in soap operas when people's kids are toddlers and then suddenly teenagers, so too can Sam and Dean spend a year apart while no time has actually passed in reality." (Source)

John Winchester's Father

In 8.12 As Time Goes By John Winchester's father, Henry Winchester, travels to 2013. Sam and Dean say that they know John Winchester grew up without a father. When Henry is killed by the demon Abaddon it confirms that Henry didn't abandon his son by choice.

However in 4.03 In the Beginning, in 1973 a guy at a diner says to a young John Winchester, "Say hello to your old man for me." Implying the presence of a paternal figure. Of course it is possible that John's mother (later revealed to be named Millie) remarried and this refers to a step-father, or even grandfather. Or that she left or died after Henry disappeared and John ended up adopted or in foster care. John later also states that he is a "mechanic from a family of mechanics," but never specifically said his father was a mechanic. While it seems that Henry and his father were not mechanics, other family members may have been, including his mother which is plausible given the number of women that entered the profession during World War II.

Castiel and Angel Banishing Sigils

When Castiel uses an Angel Banishing Sigil in 4.22 Lucifer Rising to banish Zachariah, for some reason he is not also sent away. There is no explanation for this. Possible reasons he was not were because he used his own blood or perhaps, because he was the one to use the sigil. However, this is debunked in 5.18 Point of No Return, when he carves the sigil into himself and uses it to banish five Angels as well as himself. So far in canon, the time in "Lucifer Rising" is the only time Castiel was not banished by the sigil. It is possible that he was not banished the first time because the second sigil was literally carved into his own body which the first one wasn't.

Crowley

In 8.17 Goodbye Stranger, Crowley says to Naomi "If you remember our time in Mesopotamia the way I do, you know I'm a lover, not a fighter." That line implies that they spent time together in ancient Mesopotamia. And in the events of 6.04 Weekend at Bobby's, based on information from a demon, Rufus discovers Crowley to be "17th century Scottish tailor named Fergus MacLeod from Canisbay" and it was supposedly the ghost of his son who leads Bobby and the Winchesters to locate his burial site and bones in Scotland. However, that area of the Middle East was known as Mesopotamia by the west up until the 1920 Iraqi Revolt, at which point it became known as the Kingdom of Iraq.

According to Robbie Thompson, the writer of the episode, the line was either going to reference "Mesopotamia" or "Belize," and decided to go with Mesopotamia because he thought it "sounded funny," only later realizing the mistake.

Grand Canyon

In 8.21 The Great Escapist the following exchange occurs, as Sam's resonance with the tablets cause him to remember long ago events:

Sam: Hey, you remember when dad took us to the bottom of the Grand Canyon on that pack mule ride and your mule kept farting, just letting go like gale force?

Dean: Dude, you were like four years old. I barely remember that.

However, in 2.09 Croatoan, Dean had said, "Yeah, you know, all this driving back and forth across country, you know I've never been to the Grand Canyon?

Writer Ben Edlund said of the issue "Also -- sorry about Grand Canyon gaff in last episode I wrote -- that dropped ball of canon was mine to carry." (Source)

Jimmy Novak

In 10.09 The Things We Left Behind, Castiel reveals to Claire Novak that her father Jimmy was destroyed when he was killed by an archangel. However, in 5.14 My Bloody Valentine Castiel specifically mentions Jimmy's taste for red meat has been touched by Famine, later in the episode Famine tells Dean that "hunger doesn't just come from the body, it also comes from the soul," which would conclude that Jimmy's soul was brought back with his body.

It is possible that Castiel means when he was obliterated by Lucifer in 5.22 Swan Song and not when he was purportedly killed in 4.22 Lucifer Rising, as the footage from "The Things We Left Behind" specifically show Castiel's death by Lucifer and makes no reference to his prior death at the hand of Raphael. Knowing what we know now about Chuck Shurley, it is possible he never allowed Castiel to die then and lied to Sam and Dean.

However, in 6.03 The Third Man, Castiel mentions to Sam and Dean that he has been spending the last year as a "multidimensional wavelength of celestial intent," bringing the question of how he would be able to reenter Jimmy's body if Jimmy's soul is in Heaven.

Camp Chitiqua

In 12.02 Mamma Mia Mary finds a photo in John's Journal, which is the same one of the hunters at Camp Chitaqua from 5.04 The End. It's appearance here is curious given that Camp Chitaqua and the photo existed in a reality constructed by Zachariah. The photo does not exist in the "real world," although it is possible that Dean was able to bring it back from the alternate reality with him. The most likely answer probably ties to the production not being able to use any likeness of Jeffrey Dean Morgan, as they have photoshopped him out of photos and simply used the Camp Chitqua photo as a picture of random hunters given that it is filmed out of focus.

Comparison of the Camp Chitaqua picture in 12.02 Mamma Mia (left) and 5.04 The End (right).

Lucifer and the First Demons

In Casey's conversation with Dean in 3.04 Sin City, he asks if Lucifer is real and she responds, "Well, no one's actually seen him, but they say that he made us (demons) into what we are, and they say that he'll return" (which would later be paralleled by God's relationship with angels). Lucifer is revealed near the end of season four to have personally created Lilith. While Lilith conceivably could have been limited in her interactions with her fellow demons due to how deep she is said to have been trapped in Hell in 4.22 Lucifer Rising, Lucifer is then stated in season eight and season nine to have "hand-picked" the Knights of Hell and given Cain the Mark of Cain, and in season tweleve to have also created the Princes of Hell -- one of whom, Azazel, Casey served and spoke of in the same episode as though she were very familiar with him. Despite the number of demons directly created by Lucifer alive and active in the present day, Casey speaks of Lucifer as though she has no proof he exists and that she only believes in him out of faith. It can be assumed that Casey meant none of the demons like her have seen Lucifer themselves. Given what notorious liars even demons know demons are, it's possible that there were doubts among younger demons that older demons claiming to have been made by an angel were telling the truth.

Ruby also tells Sam that creating Lilith is what got Lucifer locked up in the first place. Again, later seasons reveal that Lucifer is also responsible for the creation of Cain and the four Princes of Hell, which couldn't have happened if he was already caged for turning Lilith. While Cain only turned into a demon because of the Mark once he killed himself, which must have occurred only after Lucifer's imprisonment for creating the first demon Lilith, the Princes are clearly stated to have been turned by Lucifer himself shortly after Lilith. Additionally, Lucifer is attributed with at least choosing the Knights of Hell, if not actually creating them. It is possible that the creation of the Princes of Hell (and possibly the Knights) was not discovered until after Lucifer had already been imprisoned for Lilith's creation, and that Lucifer might have been able to communicate with Cain to choose Knights to be turned after his imprisonment as Azazel would later do in the 1970's, or Henry might have been misinformed in Lucifer's role in selecting them (as the Men of Letters were later proven to be mistaken on who had wiped the Knights out). In 5.04 The End, Lucifer tells Dean that Michael cast him into Hell, never mentioning the Cage. Another possibilities is Lucifer was cast into Hell, and only placed in the Cage after passing the Mark. It could also simply be that Ruby was exaggerating, lying, or misinformed.

Though the fact that Crowley said that the Princes of Hell are the oldest of the old demons, Henry Winchester said the Knights of Hell are the first born demons, that means also that they are the first demons. The only logical explanation is that the Princes of Hell are alongside with the Knights of Hell and Alastair the the first generation after Lilith and thus the oldest of their kind; that or the very first demons are white-eyed demons such as Lilith and Alastair , then the Princes of Hell as the oldest of all demons after them and then to the last the Knights of Hell.

Souls Moving from Hell to Heaven

Belphegor: Souls cast down to Hell? That's the end of it. Heaven can't take 'em.

In 15.02 Raising Hell, Belphegor says that souls that have been to Hell cannot go to Heaven. When Sam and dean bring up the cases of Bobby Singer and John Winchester -- who both went to Hell before ending up in Heaven. Belphegor counters that God made an exception for them, but that without God's intervention souls that have been to Hell are excluded from Heaven. However, this doesn't address the issue of the 50,000 souls that Crowley gave Castiel in order to fight Raphael in Heaven, which was revealed in 6.20 The Man Who Would Be King, unless God also intervened in that situation. Another possibility is that there is a loophole in the fact Castiel carried the souls within him, not unlike how Dean was able to carry Benny's soul in his arm through the human portal in Purgatory, despite the portal being specifically made for human passage.

Miscellaneous

• Sam's driver's license (as seen on the Official Site) lists SEX: F
• In 1.01 Pilot Dean claims he was his own gig, "some voodoo thing down in New Orleans" sometime in early October (in correlation with John leaving "3 weeks" before Dean showed up in Palo Alto on October 31st). Because the Pilot episode was written, cast and filmed in early 2005, and was first aired on September 13 2005, the writers and producers could not have known that on August 28 2005, Hurricane Katrina would hit New Orleans, causing extensive damage to the city, or that on September 24 2005, Hurricane Rita would re-flood the Lower Ninth Ward, once again postponing clean-up and re-population efforts. This would have made it unlikely that Dean would have been there for "some voodoo thing" in early October. He could have been, but it's doubtful. Conversations between Sam/Jared and Ruby/Genevieve in 6.15 The French Mistake suggest Hurricane Katrina may not have happened during Supernatural's universe as the "real" world is placed within an alternate universe. Alternate theories: Dean was helping with Katrina cleanup and for whatever reason didn't want to say so flat out. Or there was indeed a "voodoo thing" happening on or around Hurricane Katrina. Not that much less implausible than, you know, voodoo.
• In 1.05 Bloody Mary Dean begins to bleed from his eyes when confronted by Mary Worthington, denoting he had a dark secret which creator Eric Kripke claimed would be addressed at a later date. However, the plotline would quickly be dropped and never mentioned again.
• In 2.01 In My Time of Dying John knew how to summon Azazel, yet did not do it when he first acquired the Colt.
• In 2.12 Nightshifter Dean says, "You remember the old werewolf stories? Pretty much came from these guys" in reference to shapeshifters, implying that he did not believe that werewolves existed. But in 2.17 Heart he makes reference to having hunted a werewolf "when [they] were kids," and we know Sam wrote a story about them at school as told in 4.13 After School Special, so he must have been aware of the existence of werewolves. This could, however, mean that Dean was implying the old werewolf stories of shedding skin, which the shapeshifters are known to do, while Supernatural's version of the werewolf do not.
• In 2.12 Nightshifter although the shapeshifter had been dressed as a man, when the shifter turned into a woman, somehow it acquired a woman's slip without having taken the actual clothes from its likeness.
• When Sam and Dean first encounter a zombie in 2.04 Children Shouldn't Play with Dead Things, the only way for them to stop Angela Mason was if they staked her inside of her coffin, that method also proved to be the only way to stop zombies risen by Samhain in 4.07 It's the Great Pumpkin, Sam Winchester. However, in 5.15 Dead Men Don't Wear Plaid, when they encounter the zombie Clay Thompson, Sam and Dean appear to be prepared to drop him with a head shot, despite the fact they should know it would not work.

In 14.06 Optimism, Dean indicates that the method of killing actually depends on the type of zombie, telling Jack that with the type that Vance is, headshots won't work and they have to stake him to his coffin.

• In 2.04 Children Shouldn't Play with Dead Things, John Winchester's dog tags list his blood type as AB. However, in 10.03 Soul Survivor when Sam steals blood to purify Dean with, Sam tells him, "For what it’s worth, I got your blood type." Sam never says Dean's blood type, however the blood bags are labeled as type O, which is a universal blood type. While rare, it is genetically possible for someone of AB blood type to have a child who is (phenotypically) type O. One way is that if both mother and father are carriers for the recessive Bombay blood group, then the child's blood type will appear to be type O (which is what matters for receiving a blood transfusion), regardless of what ABO blood type they are.
• In the opening for 2.08 Crossroad Blues, Robert Johnson is being chased by a hellhound, and soon dies referencing "black dogs." Johnson's death is the only crossroads deal death to not have the victim torn apart by hellhounds, no explanation is given as to why.
• In 4.02 Are You There, God? It's Me, Dean Winchester Castiel mentions six angels having died in the field, but in 4.16 On the Head of a Pin it is a sudden mystery as how angels are being killed.
• In 4.04 Metamorphosis, Dean appeared to not know what a rugaru was, but in 9.07 Bad Boys it transpires that he knew that John was on a rugaru hunt in 1995.
• In 4.15 Death Takes a Holiday, Alastair tells Sam and Dean he got his scythe from "an old friend" that was "jonesin' for the Apocalypse." But in season five, Death has been locked away and needed to be raised by Lucifer, and thus couldn't have given Alastair the scythe. And upon Death's meeting with Dean Winchester, his demeanor about the Apocalypse was fairly ambivalent, and the only reason he was causing death and destruction was because he was bound to Lucifer's will; also making it obvious that he would never give a weapon so powerful to a demon like Alastair.
• In 4.16 On the Head of a Pin it is never explained how Anna regained her destroyed human body. Also in the episode Alastair was shown to be affected by contact with holy water, however in 1.22 Devil's Trap, Azazel, a demon lower on the hierarchy was shown to be resistant to holy water.
• In 5.03 Free to Be You and Me Castiel states that an angel cannot touch or pass through holy fire, or it will die. In 5.22 Swan Song Michael is able to survive being engulfed with holy fire.
• In 5.10 Abandon All Hope... it is never explained how Lucifer knows about the Colt, as he would have been locked away in the Cage when it was created by Samuel Colt. And even if he was told about the Colt after being released, he would not be aware that he is one of the five things in all existence it can't kill.
• In 6.04 Weekend at Bobby's, it is revealed that a demon can be destroyed by burning its earthly remains. However, John Winchester's spirit is shown escaping from Hell in episode 2.22 All Hell Breaks Loose: Part Two despite his remains being burnt at the beginning of 2.02 Everybody Loves a Clown. One possible explanation for this discrepancy is that burning a demon or spirit's remains only destroys it if it is on Earth (in the case of a demon, possessing a human on Earth). It is also plausible that John was never a demon, considering it is said that he did not break the first seal while in Hell, and thus he did not start the Apocalypse. It was Dean who ended up being the righteous man to start it.
• In 6.22 The Man Who Knew Too Much, Sam uses a gun on a crossroad demon, despite knowing it would be ineffective.
• In 7.21 Reading Is Fundamental the Winchester learn from the Leviathan tablet that the bone of a righteous mortal can be used to kill them. However, the tablet would have arguably been made before humans, and God would not have expected the Leviathans to become so dangerous as to give a weakness that can only be made from a human despite not coming into being for some time.
• In 8.22 Clip Show, Abaddon says that she learned about Josie Sands from Father Max Thompson, and decided to use her to infiltrate the Men of Letters. In 9.17 Mother's Little Helper, her initial encounter with Josie appears to be unplanned. Though Abaddon is aware of the Men of Letters, inferring that the episode takes place after her encounter with Father Max Thompson. This is supported by the fact that Henry and Josie indicate they are close to initiation.
• Meg claimed to be loyal to Azazel and Lucifer and remained adamantly loyal to Lucifer's memory in season six and seven, even leading the remaining Lucifer loyalists being hunted by Crowley, yet she possesses Sam -- Azazel's favorite for the role of Lucifer's vessel -- and tries to get him killed in 2.14 Born Under a Bad Sign, saying she no longer cares about the master plan and not mentioned as being involved in the demon campaign to free Lucifer in season four. Although she seeks revenge against Crowley in Lucifer's name, she works with Sam, Dean, and Castiel and shows no inclination to attack them for their much greater involvement in Lucifer's defeat, even when she believes Crowley is dead. It may be that she was only ready to get Sam killed because she may have believed any damage done to the plan with his death would be minimal as there were other Special Children who could be used instead. After season five, she may be more inclined to hold a grudge against Crowley than the Winchesters regardless as he actively betrayed Lucifer's side, whereas the Winchesters were enemies they knew were working against them.
• In 9.04 Slumber Party, Charlie Bradbury goes to Heaven after being killed by the Wicked Witch of the West. However, it is revealed in 9.14 Captives that Metatron's spell not only closed off Heaven to angels but also to spirits as well. Thus, Charlie should have been stuck in the Veil like Kevin Tran was rather than going to Heaven and experiencing a memory of a specific Christmas.
• In 10.05 Fan Fiction the students of St. Alphonso's Academy put on a play based off of Carver Edlund's Supernatural book series, the play's writer Marie refers to Sam and Dean as Winchesters. In 4.18 The Monster at the End of This Book, Chuck tells Sam and Dean he never used their last names in the books.
• In 13.09 The Bad Place, Kaia Nieves line about "Trump's America" is a possible continuity error, as 12.08 LOTUS established that the current president in the Supernatural universe is Jefferson Rooney. Kaia's line may suggest Trump was voted in at the 2016 election, however "LOTUS" takes place in December of 2016 and dialogue makes mention of Jefferson Rooney being the "most popular sitting President in modern history," either suggesting he was recently elected or re-elected in the 2016 presidential election.
• In 13.23 Let the Good Times Roll Sam reveals to the Apocalypse World refugees that Donald Trump is the current president, making no reference to what happened to President Jefferson Rooney.
• In 14.07 Unhuman Nature Sam asks if Rowena remembers their friend Jack, which she simply gives a shrug, before reminding him he is Lucifer's son. However, in 13.21 Beat the Devil Rowena says to Lucifer as she is using his grace to open the rift:

"Do you know what your grace is making possible right now? The heartfelt family reunion of Sam, Dean, Cas, Mary, and your very own son Jack. That's right. Your wee boy's over there, and he'll be so glad to see his three fathers. Of course, as far as he's concerned, they are his father. And you? You're nothing to him."

Though Rowena knew of Jack, she hadn't actually interacted with him until 14.07 Unhuman Nature and so may have simply not realized exactly who the Jack she was meeting was until they told her.

• In 15.05 Proverbs 17:3, the newly resurrected Lilith tells Sam and Dean she was sleeping in the Empty, when Chuck brought her back. However, in 13.04 The Big Empty, the Cosmic Entity tells the recently awoken Castiel:

"No. No, no, no. Not with me, and I’m—I’m the only one that has any pull here. Not Heaven, not Hell, not G-O-D himself. So think harder. Rack that perky little brain of yours."

However, its never explained in the first place how God brought Castiel back so many times if this was true. Additionally, Billie was able to resurrect Jack from the Empty without any of the same issues though given the end of 14.20 Moriah when both she and the Entity approach Jack, she at least may have had its consent. In 15.13 Destiny's Child, the discrepancy with Jack's resurrection is resolved with the revelation that Billie and the Entity are working together and thus the Entity allowed Billie to bring Jack back from the dead.

In 15.17 Unity, this discrepancy is finally resolved when the Entity admits to Sam that its claim of God having no power over the Empty is just "sweet little lies."