Hajime is glad Alex approached when he did; he has no clue how to deal with the guy now that he really has no cause to punch the driver. Diplomacy has never been Hajime's strong suit; that's why he'd spent so much time in school getting into fights. He backs off a little to give Alex a bit more room to talk...

...but he really does want to make sure the guy didn't try anything funny, so he adds another growl at the driver as he does so. Someone's probably a little too good at playing Bad Cop.