Two Sailors Walk Into a Bar... - S1-E8
Revealing mistake: When the Americans are leaving the Russian ship they are doing it right next to a tensioned mooring line which you would only see in an harbor but not on a ship that operates under its own power in open water, thereby betraying the filming location as a docked (museum) ship. (00:35:50)
Unreal City - S2-E1
Revealing mistake: When Chandler and the others make it to the building where the bodies are being burned, the actor playing a corpse flips his hand over to hold onto the conveyor belt as he goes over the edge. (00:16:05)