Mac is a Serial Killer - S3-E10
Plot hole: Early in the episode, it is mentioned that the serial killer is murdering "Young, attractive blondes", yet at the end of the episode, when the gang finds all the severed heads in the killer's refrigerator, almost none of them are blonde or young, contradicting what had been previously established.
The Gang Gets Stranded in the Woods - S6-E11
Plot hole: When Charlie and Dennis are on the plane, Dennis asks Charlie to give him his phone so that he can text Mac. In the next scene, Mac receives a text which he says is from Dennis. But Dennis was using Charlie's phone, so there was no way Mac could have known it was Dennis texting him. (00:20:20 - 00:21:45)
