Episode #3.4 - S3-E5
Continuity mistake: When Lance says "This is a bloody joke", he throws his racket on the floor. The racket then reappears and disappears over the course of his following lines.
Episode #3.6 - S3-E7
Other mistake: When Pete goes to turn off the car alarm, you get a look at the key he uses, this key is for a Vauxhall Corsa, and this isn't the car that's going off, it's not even by the same manufacturer. (00:12:15)
Chosen answer: Angels and Demons.