Let me guess how that happened: the white car had some kind of right of way (if only by habit) so waited for the grey car to back up. The grey car´s driver had some ego issues preventing him from backing off from anything or anyone!!! so they let their motor roar for a bit and made angry gestures. At which the white car´s driver dug in their heels and made some sort of gesture signaling "whatever, idiot, drive around me if you think that´ll get you anywhere", the grey car´s driver´s rage blocked out their critical thinking skills and they decided to show the white car´s driver what´s what with their Awesome SUV (TM). Just a guess, of course...