The cars can pass the truck only because they are "cheating," i.e., cutting into the trucker's space, so by that logic, no trucker is allowed to pass anyone ever.

Hitting their brakes briefly and then accelerating, nothing terribly unusual in that. People can hit their brakes at any time. Maybe they saw something out of the corner of their eye, whatever, this is another reason to give all cars wide berth. The gray car driver looked insane or drunk.

If Lego says it's canon, it's CANON!