Revealing mistake: When Dom crashes his Charger into a semi, the semi is approaching in the shot from behind the Charger. When the camera angle changes to the front view, the semi is stationary. In this shot, the semi has no front left wheel, and as the Charger passes through the hood of the truck, there is no engine in the truck.
Revealing mistake: During the high-speed chase with the tractor trailer, Vince fires one grappling wire through the truck's passenger windscreen to pull the glass out. He fires a second grappling wire through the now-open windscreen and grapples the passenger seat, then attaches the grappling wire to his harness and leaps to the front of the truck. So, his only tether to the truck is the horizontal grappling wire attached inside the truck cab. But, when the truck driver slams on the brakes, Vince is catapulted around the truck's front-end to the side door, his full weight suspended from a visible, vertical line that is attached to something several feet above the truck cab. The taut line from above even crushes the truck's side-view mirror under Vince's weight. This is the stuntman's safety cable, attached to an overhead boom mounted out-of-frame on top of the truck rig.
Continuity mistake: In the scene after Dom and Brian arrive at Dom's place, Vince walks up to Dom and tells him "he had no right bringing the buster there." Just before Vince walks up, you see Dom sitting down putting his hand on his head. Next shot cuts to Vince walking up and cuts back to Dom who getting ready to sit down again then puts his hand on his head.
Other mistake: When Brian is evading the cops after picking up Dom, he comes out of a side street and is honked at by a Volvo station wagon, which then ends up crashing into the cop car following. Thing is, the light was red for the Volvo the entire time, so they shouldn't have been rolling through the intersection, much less honking at Brian like he was in the wrong.
Continuity mistake: When the first street race takes place with the four cars, it is evident that the race takes place along a straight stretch of road. However, when the race finishes, everyone who was at the start line just a minute ago has magically appeared at the finish line, miles down the road.