I'm glad you're okay. I really hope that driver learns an appropriate lesson before damaging more people and cars.

This is also my takeaway argument when people claim that the unregulated free market is best. "Wait to the last minute, then cut in" is precisely what the "unregulated free market" calls for - maximize your own advantages, so long as it doesn't hurt you. Thankfully, most people have a notion of playing fair, taking turns, etc., so not all drivers drive like this.