When Jeff first closes the shower curtain it hangs on the outside of the tub, but when Erin leaves it's on the inside without either one moving it.
The donation jar in the bar has a lid in some shots, but it disappears in others.
The movie depicts the famous photograph of Carlos Arredondo helping Jeff Bauman with Carlos facing Jeff and his face hidden behind the cowboy hat. In reality, Carlos is looking ahead and his face is clearly shown.
When Jeff comes out for the national anthem during the hockey game, both benches are empty and both teams hockey players are nowhere to be seen. In real life, the anthem is sung just prior to puck drop with all of the players and coaches present; either on the ice at the blue lines or on the bench. This reality also separates hockey from other sports such as baseball, basketball and football which, apart from huge games like season openers or championships, usually complete the anthem singing during warmups or while the players are still in the dugout or tunnel. Additionally, one of the advertisements on the boards is for the NHL's playoff bracket contest despite the fact that the division re-alignment that created the bracket system (in which teams must first play the teams in their division before advancing to the conference finals) was first instituted during the 2014-15 season and not during the 2013 playoffs in which the film is supposed to be taking place.