Shortly after Caroline calls the actives zombies, pay attention to the girl in pink. She walks past the man twice.
When Alpha inserts the hard drive to 'wedge' Wendy, he inserts the drive upside down to how it would fit into the slot.
(at around 14 mins) The chessboard is set up 90 degrees wrong. When you play chess the square in the right hand corner (H1 for white player, A8 for black player) should always be a white square. In this shot it is a black square.