Continuity mistake: The assassin rips out a magazine page with Leila's photo on it and sets it ablaze with a cigarette lighter. The face in the picture burns while he's still holding the page. But in the next shot, after he drops it, the face is still intact and starts to burn all over again. (00:22:30)
Continuity mistake: The blood stains on Kevin's white lab coat change size and position several times between takes. (00:40:00)
Continuity mistake: When Darien reaches into the glass spider enclosure to retrieve the note, the number of spiders sitting on the paper changes (too quickly for them to have crawled away and back naturally). First there are two on top of the paper, then only one, then instantly two again. (01:11:30)
Money for Nothing (1) - S1-E22
Continuity mistake: In Darien's apartment, the wall clock, which is running, reads 8:20. But his watch, which is also running, says it's 5:55. (00:21:45)
Visible crew/equipment: When Darien opens the door and comes outside to meet Hobbes, the glass reflects the camera crew twice as it opens and then closes again. (00:07:40)
Continuity mistake: A visible Darien leaves the sleep clinic in a downpour, getting soaked in the process. But when he climbs into the van to report to Hobbes, he's completely dry. (00:17:00)
Plot hole: In the pilot, it is established that the surface of anything/anyone made invisible by "quicksilver" is freezing. (Darien gets caught in the women's shower because the mist freezes on him. He freezes the beer mugs for the doctors.) But in later episodes, nobody notices him standing invisible - and freezing!? - next to them.