Continuity mistake: When Gigi calls Alex for the first time to get his opinion about a guy "Jarrad", Alex puts her on hold and goes into his office to pick up the call. In the bar the phone line is lit up where it's holding, but the office phone is not lit up at all.
Visible crew/equipment: In the first half of the movie, when Jennifer Aniston tells Ben Affleck her sister's getting married, a cameraman's reflection appears in a painting on Ben's left. It happens again a few seconds later.