Deliberate mistake: During the civilian sheriff's pursuit of the Navy car, the sheriff is occasionally visible in the passenger seat of his patrol car instead of the driver's seat.
Through a Lens Darkly - S1-E20
Continuity mistake: At the end of the episode, Tom is absolutely drenched because the car has crashed into a river, and he has to wade through the river to get to the riverbank. However, as he walks away, he doesn't leave a single wet or muddy footprint behind him despite this.