During the Charlestown/Hyannisport game, #7 of Hyannisport (current Minnesota Wild coach Bruce Boudreau), is shown on the ice, celebrating a goal. In the next shot, which is a line change, #7 is shown leaving the bench to go onto the ice.
Reggie Dunlop leaves a tavern to go record a radio interview. When he leaves the bar, he announces that the interview will air on the radio later that day at four o'clock. During the interview, he states that he will offer a "bounty" for the first Chiefs player to assault the other team's captain on the ice in the upcoming game. After the interview, Dunlop goes home and tries to get some sleep. He listens to his own interview on the radio, including the remark about the bounty. After he turns off the radio and tries to go to bed to have a nap, the clock on his bedside table reads a quarter to four, 15 minutes before the interview was supposed to air.
In the opening sequences introducing the players, Ned Braden can be seen wearing blue gloves as he stands by the boards. When he skates out for the introduction, he is wearing old brown gloves. When the next player is introduced, he can be seen wearing new matching blue gloves again.
When the Hansons first take the ice, the drink can on Jim Carr's (announcer) desk changes from Fanta to Coca Cola and back again several times.
In the opening hockey sequence, a Chiefs player is shown taking a slap shot, which appears to strike the sliding opposing defender in the groin, then there is a cut which shows a Chiefs playing writhing in pain from a groin injury
In the first game of the movie, there is a shot of the Chiefs bench laughing at the drunk player who accidentally urinates himself. In that shot, you see a Chiefs player that isn't shown in the rest of the movie. Many people regard this as a movie error. But in reality, it's not uncommon for a person to play only one game for a minor league hockey game.
When Killer goes after Donaldson after he tells Dunlap he's too old - he charges into him and breaks his stick over the side of Donaldson's neck. First, it would take a tremendous more amount of impact for a stick to break in addition, a blow like that would have broken Donaldson's neck.
In the scene where the goalie is being interviewed, he talks about going to the penalty box. Some have mistaken that he is talking about himself, as goalies never go to the penalty box, but he is in fact simply discussing the different kinds of penalties a hockey player can go into the penalty box for committing.
During the championship game, cardboard cutouts to fill in the "crowd" can be clearly seen in the upper levels of the arena.
During the game when Dunlop learns the team is folding, the newly acquired Hanson brothers are missing from the bench, even though they were dressed and ready in the locker room beforehand. They also cannot be on the ice, as Dunlop has not yet allowed them to play.
Ned Braden performs a striptease during the championship game fight. We see that his underwear is a "union suit" - a one piece outfit with short sleeves and short legs that buttons down the front and has a flap in the buttocks region. However, after he sits atop a goal net, somehow he has removed that article of clothing without removing the jockstrap which he was wearing over the union suit.
In one of the game scenes, a shot shows one of the Hanson's passing the puck (ultimately assisting on a goal), yet Dunlop had not yet allowed any of the three Hansons to play.
During the celebratory parade at the end of the movie, one of the musicians in the first school marching band is playing a French horn. Normally someone who plays French horn in a school concert band will play a "marching horn" in the marching band. A marching horn is a completely different instrument in that its bell faces forward, as opposed to the French horn's bell that faces to the rear.
At the bar many of the players are drinking Stroh's or Schlitz but in the next shot they're drinking Budweiser or Iron City Beer.
While traveling on the team bus, many of the players are drinking Stroh's, while in the next shot they're drinking Budweiser.
When the Chiefs come back to the locker room between periods during the championship game, the Chiefs' goalie begins yelling, but his lips are not moving.
During Ned's striptease during the championship game, the band members are clapping when seen in the long shots, but their music is still playing.
Just after the wives discuss the "Great Ideas of the World" set, Jean-Guy Drouin chases a player behind the net and when they come out the other side, a director in skates and a couple members of his crew can be seen on the ice in the corner of the rink.
A major plot point of Slap Shot is that the Chiefs are drawing almost nobody to their games, but the Hansons draw them in with their style of play when they start in games later on. However, during the game when the Hansons are allowed to play for the first time, the arena is full of screaming fans who cheer every move by the Hansons.
Through out the course of the movie, Reggie Dunlop has the team, the media, and the public duped into believing that the team is being sold to a retirement community in Florida. However, at no time does Joe McGrath, who, as G.M. of the team, has a working relationship with the owner, ever make a public comment, or stop Reggie Dunlop from perpetrating the lie. Nor does anyone know who the owner is until Dunlop blackmails him into getting the owner's name. At some point prior, the media had to know who the owner was, certainly the names of the ownership group would have been in the team's program and media guide.
In the scene where the goalie is being interviewed, he illustrates various penalties with his stick. What he refers to as "spearing" is really the penalty "butt-ending." Spearing involves jabbing with the blade of the stick, butt-handing is jabbing with the handle (knob) end of the stick.
During his radio interview in which he puts a bounty on opponent Tim McCracken, Reggie Dunlop incorrectly calls his own team the Charleston Chiefs instead of the Charlestown Chiefs.
During the opening hockey game sequence, when the drunk player on the opposing team gets checked into the boards, the players on the Chiefs bench laugh at him. There is one player on the Chiefs bench though who never appears in the movie again, and appears only for that one single shot in the film.
As Reggie Dunlop had done previously in his own radio interview, Killer Carlson refers to the Charlestown Chiefs incorrectly as the "Charleston Chiefs" to the same interviewer.