Deliberate mistake: In the beginning Chris and Jaime are on the bed talking and she is excited about graduating she is wearing a mini dress. In the shot where she falls face down in his lap and her dress goes up, she's wearing black tights underneath her dress, which are not there in any other shot.
Just Friends (2005)
1 deliberate mistake - chronological order
Directed by: Roger Kumble
Starring: Ryan Reynolds, Anna Faris, Amy Smart, Chris Klein
Revealing mistake: When Chris and Jamie are on their day date in the diner, Jamie has a grilled cheese sandwich with ranch on the side. However it is obvious that the bowl of ranch is empty. (00:33:10)
Chris: I can't hear you Samantha. I can't hear you. OH! Lightbulb.
Trivia: Ryan Reynolds' fat makeup took 4 hours to apply.