Deliberate mistake: At no time can a player on the ice play without a helmet. It may be legal in professional hockey, but never in youth league games, world championships or not (This happens when the goalie comes out of the crease and takes his mask off to shoot his "knuckle-puck", as well as the penalty shot in the first movie.)
Revealing mistake: When they take a snapshot and it spins, then lands on the USA Today front page, like "Bombay Leads Team USA!" and they have his picture there... the words underneath the pictures all of the times they do this never match the story. They are just random articles that are talking nothing about hockey.
Continuity mistake: In many of the game sequences players are simultaneously on the ice and on the bench. It happens most often with the kids that are not focused on so much, like Guy and Connie, but also sometimes with players like Charlie and Adam. Sometimes it's hard to tell if it is a montage and there has been enough time for the players to change, but at other times it's blatant. For example when Adam is hit on the wrist by the Iceland player you see Connie stand up on the bench and yell, but in the very next shot she's standing next to Adam asking if he's okay. And in the street hockey scene, when the puck is thrown back after hitting the car and Charlie scores a goal you see a reaction shot of the team celebrating. Charlie is visible at the bottom of the screen kneeling and cheering.
Continuity mistake: In the final game, Coach Bombay calls a time-out and supposedly that is where the switch of shirts between Russ and Goldberg takes place, so that Russ can fool the Iceland team and take his "knucklepuck" shot. However, when the timeout is called there is an overhead shot of all the Ducks, and you can see Goldberg in the center, facing Bombay, and Russ on the left of him (you can tell it's them buy the helmets and names on the shirts). After a shot of the Iceland team, it goes back to another overhead shot of the Ducks leaving to go back into play. None of the Ducks have changed position or barely moved, not even Russ and Goldberg, who need to move and trade shirts, which indicates that the shirt trade never happened.