Sam Flynn: Dad?
Kevin Flynn: Sam.
Sam Flynn: Long time.
Kevin Flynn: You have no idea.
During the fight at the End of the Line Bar, Gem walks and stand next to Castor. Later she move to the left and sits on a couch for the rest of the fight. However, at the very beginning, right after Quorra jumps and protect Sam, there's a brief cut where we can already see her sitting there, too early.
The two 'disc jockeys' in the sound booth of the 'End of Line' club are actually Daft Punk, the French group that did the movie's soundtrack.