In the diner scene where Artie's girlfriend Linda throws French fries at him, if you look at the window sill above Artie's shoulder to the left you can see a lone French fry that appears and disappears BEFORE she actually throws them at Artie. This scene is obviously compiled from multiple takes and somebody missed a French fry when they were cleaning up from the previous take.
During the first game scene, Dirt's uniform changes from a t-shirt to a pro style button down, then back to a shirt.
During the breakup scene in the diner, Linda throws the VHS tape and it falls onto the booth bench across from Artie yet a moment later, when she starts walking out the door, the tape is back on the table.
Linda claims to work at the A&P Supermarket in Lyndhurst, New Jersey. There is no A&P in Lyndhurst.
In the scene where Artie is mowing Mangenelli's lawn and destroying the campaign signs, it is obvious that the lawn mover isn't really on. The grass doesn't get cut at all that Artie rolls over.
Mangenelli tells Artie that after "one more out" his team will be 5-0. Yet Artie hits into a double play.