When the crowd is attacking the man, Harold has his shirt on in one shot, but not in the next.
When the crowd of kids is beating up the hoodlum in Washington Square Park, they can clearly be seen kicking air.
When the kids hit the hoodlum with a skateboard, he turns his head as if being hit by it despite it not even being in the shot.
When Jennie and Ruby are talking while waiting in the clinic for their test results, Ruby's lips do not match the audio in one of the shots.