Howie doesn't have the earring in his cartilage during the fight with Marty and Kevin.
As Marty searches for his stolen money just before being arrested, the big screen TV in his room is off, but when Howie gets home and looks for his dad, the TV is on.
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).
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 Big John is slowly pulling his car alongside Howie (just before Howie accepts the offer of getting to drive the car), a crew member is seen on the right pushing the car.