A Dark Road - S3-E10
Other mistake: In this episode, Michael, Fiona and Sam are boxing in the bad guy's Corvette, trying to make him crash. Despite repeated hits to the side and back of the Corvette, just before the Corvette crashes, there is no visible damage on the bad guy's car.
False Flag - S1-E10
Continuity mistake: While the team is driving to drop Doug off at the Attorney General's office, there are multiple times that the camera shows Michael riding with Fiona in the trailing car, however when they arrive she is alone and Michael is on the roof behind Evelyn. (00:36:20 - 00:37:25)
Continuity mistake: When Chandler's car explodes, he and Michael land prone on the ground facing the explosion. When the shot cuts, they're facing the opposite direction. (00:33:35)
Continuity mistake: When Michael is talking to Barry, Barry's hands change position with each shot. On the table, folded together, holding his glass, etc.
Continuity mistake: When Michael is on the phone with the heroin dealer at the docks, he has his phone at his left ear. When the camera moves to a shot from the back, there's no phone near his face (or in the frame for that matter) and his mouth doesn't move while talking. When the shot cuts back, the phone instantly is back at his ear.
Continuity mistake: This basically happens in nearly every episode. Whenever Michael's mom is smoking, which she does a lot, her cigarette and smoke change size and position with every shot. Although it's hard to keep a cigarette burning the same way with each take, it seems as if no attempt was made at all.
Old Friends - S1-E3
Other mistake: This Jan Haseck assassin, who has either multiple allergies or else one allergy to a very common substance (peanuts), could never do any espionage work, as it would make him too vulnerable.
Chosen answer: It might not actually have one, in which case, he'd have to go down into the club and use theirs. As for showering, going to his mother's house or a gym membership would take care of that.
Captain Defenestrator