Saxman, this could be due to the other guy colliding guns blazing. He might simply have shot you.
I had a classic such situation a while ago - not sure if i caught it in film. I had a P47 coming at my HMk1 head on, and since i was too slow from fighting another guy, i couldnt properly AVOID him. Result: He collided with me, dying; I didnt collide, but flew away heavily damaged since hed been guns blazing from d100 (i just caught the muzzle flashes in passing). His damage resulted from collision, mine from plain old bullets.