| You could try running and try to force yourself in between him and the door. Jump-crouch (to make your feet reach the highest possible point in FPS) might also help to "persuade" him that his is in your way...
But other than "collision tactics", there isn't really any "safe" way other than disabling clip to get out.
You could also attack him of course.
Stupid cattle. Dumb walking blood-bags. Why, I'd pay that Humanity point just to drain you dry, hmm... talking about that, I'm feeling a little thirsty... |