Audio problem: When Rob starts accusing Benny of knowing what happened to him the previous night, Benny says that they just hung out and Rob says "Shut yo ass up" to Benny. The shot is focusing on Benny, with the camera behind Rob and his jaw does not move when he is saying the line. (00:56:20)
Audio problem: When they are in the run down seedy motel, they show Ryan talking with her back to the camera and just the side of her face showing, and her mouth doesn't say anything near what she was verbalizing in audio.
Audio problem: During Beca's performance of Freedom, she is singing with Cynthia Rose. During the little chorus pre-verse (before they put their hands in the middle), you can hear Beca's voice singing the lyrics but Anna Kendrick's microphone is nowhere near her mouth. Her lips don't even match it.