The Incident - S1-E4
Continuity mistake: When Dylan arrives at the Pritchett family dinner, and Phil notices that he brought his guitar, Dylan's gig bag switches shoulders between shots.
The Incident - S1-E4
Continuity mistake: When Mitchell goes outside to speak to his Dad in the pool, his Dad has a glass beside him. When the shot cuts back to his Dad it has disappeared. (00:13:00 - 00:14:00)
The Incident - S1-E4
Visible crew/equipment: At the start of the episode, Hayley and Luke begin fighting on the couch, and Hayley's filming equipment becomes visible. (01:14:00)
Answer: He has seen himself dancing, and is mortified at how bad he looks.