If you get this worked up over tail gating over such a small distance, then you need some anger management sessions dude.

Tail gating is nothing new, and you'll find alot of drivers do it. Also, and someone correct me if I am wrong, but I am pretty sure, that, if the driver of that other vehicle chose/chooses to report you, then you can get into trouble for your actions. (not sure how it works with proving it and all)