The second black eye that Howie receives disappears and reappears from shot to shot. It is absent in the scene in which Howie and Big John shave; however, it is present in several scenes beforehand and afterward.
In the shots of Big John leaving after dropping Howie off at the prison, there is a steady rain (noticible by raindrops in the puddles). However, in shots of Howie, it does not appear to be raining and the ground is even dry in places.
When Marty parks his car to confront Howie and Gary in the parking lot, he obviously parks it in a vacant lot (no other cars are around). However, when he returns to his car a few moments later, several cars have now appeared in the parking lot although there hasn't been time for them to arrive and park.
When Howie visits his Dad in jail, he can't even wear his earrings into the visit area. But when his Dad comes out to see him, his Dad is clearly wearing his wedding ring (and that would not be allowed in the jail anyway).