When Janice Pettiboe arrives at town hall and gets out of her car, she talks to Chuck and the mayor, both of whom also speak, but hers is the only breath that can be seen due to the cold.
When the Rangers first arrive in Mystery and are passing by the Mystery players, they appear to be much taller and larger than the Mystery players, which several of the Mystery players note. When the teams shake hands at the game's end, the players on both teams appear to be roughly the same height and build.
When Charlie and John are sitting next to the Zamboni talking, Charlie throws up on the ground. As the shot pulls back, there is no vomit on the ground next to him.
At the end of the game against the NY Rangers, the back of Banks' jersey is covered in ice. In a subsequent scene, his jersey is clean.
At the end of the second period it is still daylight. Typically the break between periods is just 15 minutes to resurface the ice. When the third period begins, the sky is pitch dark.
At the end of the movie in the credits the year is MCMXCVIX, an impossible combination of Roman numerals (it should read "MCMXCIX").
When the Ranger shoots at the empty net he is on the wrong side of center ice, yet no icing is called and the clock continues to run.
When Bailey dies in New York, it's winter in Mystery, Alaska, yet when his body is returned to Mystery, he's buried right away. This is generally impossible, as the ground is frozen solid and hard as concrete, and those who die in Alaska during the winter are interred after the thaw. Sometimes that means up to 7 months between death and burial.
Considering Judge Burnes personally knows Connor Banks, and his son plays hockey with him and are friends, it would be a major conflict of interest for Judge Burnes to be the presiding Judge in his criminal case. In real life he would either have to rec-use himself from the case or move the trial to another jurisdiction.
Russell Crowe's hair is much too long to pass the appearance guidelines of any sheriff or police department.
Before the final game at the end of the movie, Little Richard sings the American anthem then, offscreen, is heard singing the beginning of the Canadian anthem, though there is no need to do so, as the game is in Alaska and features two American teams. However, this was intentionally arranged (along with the very long rendition of the American anthem) by the Mayor of Mystery, to prolong the pre-game ceremonies and to let the Rangers freeze even longer.
(at around 10:35) During the first Saturday Game a Mystery player takes a shot on net that is clearly sailing up over the crossbar in one shot, and the next cut is the goalie making a quick glove save just under the crossbar.
In the Movie Donna and John keep saying they have 3 kids yet you only see their 2 sons Mike and Joey throughout the film.