I don't think it matters at all where you collide.
If your computer sees yourself, or someone else hit you, you will take damage. Same goes for the other guy.
It gets a bit weird, when one computer sees a collision and the other does not...causing one person to suffer damage and the other (because there computer did not see a collision) takes no damage. This is the cause for most complaints, but when looking at other options, there is no way to make it better. In one scenario, if both take damage whether or not both computers see a collision, you may be getting collision messages at d400. On the other side, if no collisions allowed, then you could fly straight through the enemy, shooting him from the inside out, and then fly off as if nothing unusual happened.
It's all due to transfering information between yourself and AH. In that situation, I would think your computer saw a collision, however, to the other guy was just close and shooting. If he landed any pings, he gets the kill, If not, maybe proxies.