Continuity mistake: Pepper states in this episode that he doesn't have any kids, but in 4-14 "A Slight at the Opera" he talks about a son he has who is a Navy Seal.
Continuity mistake: Whilst Clare and her new 'best friend' are talking to the flight attendant, the two glasses change from empty to full in the next shot.
Other mistake: When Claire is sitting in first class, the woman she was sitting next to finished her drink while on her angry phone call and asks for more, but about a second later she is drinking it again and it is no longer empty.
Answer: He has seen himself dancing, and is mortified at how bad he looks.