Continuity mistake: Coach Orion throws the puck at the bulletin board and makes a hole in it, but when he walks out of the locker room, the hole is gone.
Other mistake: After Guy gets hurt in the warriors/ducks game, the scoreboard is shown. It says that there is 15 seconds left in the third period, when it is really the second period.
Other mistake: In the final seconds of the Varsity/JV game when Goldberg takes his shot, you can see the ref has already signaled it a goal before the puck went into the net and the goal judge turned the lamp on.
Continuity mistake: During the Warriors VS Ducks game, Charlie is driving down the rink and it cuts to a wide shot. You can see the puck is dropped and intercepted by a Warrior. In the next shot, Charlie takes a shot which the Warriors' goalie blocks. Charlie couldn't have gotten the puck back that fast, no matter how good he is.
Continuity mistake: During the second period of the Varsity-JV game, the camera flashes on the scoreboard. It is supposed to be the second period, however, the clock numbers indicate that there are 13 minutes left in the third period.
Continuity mistake: During the outdoor ceremony welcoming the Ducks to Eden Hall, you can see Charlie's "C" in a close-up shot. In a subsequent shot of the group, the "C" has disappeared completely.
Factual error: Throughout the entire Varsity/JV game, the Varsity team makes at least 20 penalties that aren't called. They also refer to a tripping call as hooking, even though the Varsity player obviously goes for the JV players ankles.
Audio problem: Right after the final buzzer, Julie the Cat skates out of the goal and pushes off her helmet, yelling "all right". She's smiling and her lips don't move.
Continuity mistake: When Portman tackles one of the varsity team's player through the glass, his helmet's attachment changes, in the face off, it's different than after the tackle.
Other mistake: When Portman is talking to Cole, the straps for his full face shield are missing, but after he checks Cole into the glass, you can see those straps attached to his helmet and face shield.
Continuity mistake: When Portman is talking to Cole, Portman moves down his left hand twice.
Continuity mistake: During Charlie's "one on one" with Riley in the JV/Varsity game, there's a quick shot of the bench with O'Ryan and you can spot Ken Wu on the bench, when he is still supposed to be in the penalty box from the bench minor penalty.
Visible crew/equipment: During the street hockey game when Charlie rejoins the ducks with Bombay, cameramen are rolling around filming amongst the players.
Other mistake: One of the Bash Brothers is Fulton Reed. Reed is his last name and should therefore be the name on his jersey (as it was in the first two movies). In this movie, though, his jersey says Fulton, not Reed. Also, whenever anyone calls out the players' names, they say everyone else's last name, but here again they call him Fulton, not Reed. On streaming versions this has been corrected.
Plot hole: There is no reason that Eden Hall couldn't have accepted the Ducks and also kept some of the JV players as well other than they didn't want to hire more actors for the team. Keep in mind, by the time the Ducks actually attend E.H. they only have 12 players (with two goalies). Once Banks gets transferred to Varsity they only have 9 skaters. Surely they could have allowed the cut JV players to rejoin the team since they barely had enough skaters for 2 full lines.