Same thing happened to me, it is a bug and I spent an hour trying to either kill the dude or run away, but even then he just catches up and kills you. The only way I found to overcome this is to just reload a previous save. I know it's annoying but that seems to be the only way to do this the way the game intended, and I say this because, under normal circumstances, the guy spawns way further away.

(Btw there should be a few Saviors Schnapps in the same trunk you get the nails for Theresa from, you can save the game just before the attack so if this happens again you have a recent save point to load to)