Revealing mistake: While Jacob is playing Second Life in the beginning of the movie, shortly after the four-minute mark, the camera briefly cuts to the screen of his laptop and shows the controls for the video player they used to play back the captured clip. Additionally, in the same shot, the menu bar at the top of the screen implies a Macintosh computer, while Jacob is using an Alienware PC. (00:04:09)
Continuity mistake: When Lou and Nick are playing pool in the bar, Lou goes to break the rack and misses. When Nick goes to break them, the balls are racked in a different pattern. (00:50:10)
Factual error: The famous AFC Championship game that featured "The Drive" took place on January 11th, 1987, while the events of the film took place in 1986.
Factual error: Blaine (from the ski patrol) mentions "21 Jump Street" in 1986; that show premiered in April 1987.
Factual error: In the scene where they are watching "The Drive", the TV is not showing an NFL game at all. The field is 110 yards long. There is an overhead shot of the field and you can see two 50 yard lines and a C in the middle. They are watching a CFL game.
Factual error: In the scene where they bet on the outcome of "The Drive" AFC Championship game, it's obviously late evening. Yet, the Browns/Broncos game was started at 12:30 EST, so it would have been morning in Colorado (where the movie takes place).
Plot hole: The movie is based in 1986 after the group time travels from 2010. That makes it a 24 year trip back in time. It is stated that Jacob is 20 years old. That is an error as this would make him roughly around 23 or 24 if he was conceived in 1986, which we saw near the end of the movie.
Suggested correction: This mistake has already been corrected. Cusack could have simply generalized his age when he mentioned it, probably not remembering his real age at the moment.
Continuity mistake: When the guys reach the end of their downhill run, they encounter Blain, who is irked by their "shenanigans," going so far as to shove Jacob to the ground. When he pushes Jacob the large two-way radio that is in his pocket falls and hits the ground in front of him. However, when the camera angle changes to show only Blain and Chaz, the radio is back in his pocket without him ever having to recover it from the ground.
Factual error: The song "Smooth Up In Ya" by the BulletBoys is heard in a 1986 scene; that song was first released in 1988.
Plot hole: In the scene when the guys bet on the outcome of the football game, their prediction is proven wrong when the vomit covered squirrel from the earlier scene runs onto the field and disrupts John Elway's pass. The movie takes place in Colorado, but the AFC Championship game featuring "The Drive" was played in Cleveland, OH. That's a lot of distance for a squirrel to travel in a couple hours.
Suggested correction: The movie is a comedy. Sure it's unlikely for a squirrel to travel that distance in the given time, but so is a time machine in the form of a hot tub. The scene is there to demonstrate the effects of altering the future, not to prove how fast a squirrel can be. In a comedy, this is exactly the kind of liberties one might expect from a scriptwriter.
Factual error: If the guys went back to 1986, why is there a poster of Rambo III in one of the lodge bedrooms? That movie didn't come out until 1988.
Continuity mistake: When the guys are at the lodge in their room, and they're sitting around the table talking about the past, the glasses on the table keep moving around in each shot.
Continuity mistake: When the guys reach the end of their downhill run, the sun changes between shots.
Factual error: "Push it" by Salt 'n' Pepa, featured in the film, was released in December of ‘86 but the events are suppose to take place in January of ‘86.
Revealing mistake: The can of "Chernobly" is supposed to be from Moscow, and the lettering on the can contains at least one Cyrillic letter. However, the name printed on the can is nonsensical, using random Latin and Cyrillic letters in an effort to look Russian, but the letters don't spell a word and means nothing in Russian.
Factual error: When Phil is carving the ice sculpture, he slips and the chainsaw flies into the air, and it continues to run. Chainsaws will only run while you hold down the trigger.
Suggested correction: Easily rigged to be able to have the trigger held down without pushing on it.
Factual error: At the end of the movie, after Lou has altered history, we see the video for "Home Sweet Home" by Motley Crue. "Home Sweet Home" was on the album "Theatre of Pain" which was released in 1985. The video had already been released by the events of the movie in 1986.
Other mistake: The lodge the guys are staying in is called The Silver Peaks Lodge. However, in the scene where Nick is confirming his reservation, the sign behind the clerk with the goatee reads The Silver Peak Lodge [singular].
Continuity mistake: When Adam eats the mushrooms in the room and speaks with Jacob, when he leaves Adam is wearing just the sunglasses, but in the next shot is also wearing a hat.
Continuity mistake: When the movie starts, Nick has his left hand over the bulldog's back and the right around the leash. When the phone rings, his left hand is now holding the leash, and the right one is grabbing the cell phone. The transition between both movements is missing.
