Visible crew/equipment: When Stanley throws the mask out of the window and it comes back in, there is a low shot of his bed. The shadow of the camera operator is on the bottom of the frame. It looks like the operator is moving.
Continuity mistake: When Stanley is beating up Dorian, Dorian's head is either lying against the ground or raised, depending on the shot. (01:27:49)
Chosen answer: It's an old car, so obviously a numbr of things could be wrong with it, like the clutch or the engine. Faults with either of these things would cause a car to brake in this way.