Around 57 minutes in, when Debbie and Joan are talking, while Joan is saying "Its 5:30 in the morning, only Starbuck's employees and babies are up at this hour.", her head scarf is on, then disappears in the next shot, then is on again in the next.
(at around 41 mins) The towel on Casey's shoulder disappears and reappears between shots.
Closer to the end of the movie when Hall and Hart were sitting at the table Bernie, played by Kevin Hart mentioned that he was allergic to chocolate. Later he was eating chocolate with no reaction.