Character mistake: Will Ferrell is talked into shooting his gun at the ceiling. Keaton comes from his office and takes his gun and gives him a wooden one. When he takes the real gun, he unloads the magazine from the gun but fails to remove the round in the chamber. He's a cop, he should know how to safely handle a gun.
The Other Guys (2010)
1 character mistake - chronological order
Directed by: Adam McKay
Starring: Samuel L. Jackson, Mark Wahlberg, Dwayne Johnson, Will Ferrell, Michael Keaton, Eva Mendes, Derek Jeter
Continuity mistake: The car is replaced with a grey door after it is in an accident. When you see the car on a train to Las Vegas the car door is red again. Every time you see it after this it is back to being grey.
P.K. Highsmith: Ay, ay, ay! You shut your face! If I wanna hear you talk, I'll shove my arm up your ass and work your mouth like a puppet! You hear me? You hear me?!
Trivia: Make sure to stay after the ending credits to see Will Ferrell and Mark Wahlberg in a restaurant being quite comical.