So....if my front end records a collision and the other person's does not, am I the only one colliding?
Crazy.
Both take damage. This leads to ramming being a viable tactic and being very hard to avoid as the player on who's FE the collision does not occur is not able to see that the collision is about to happen.
Only the player on who's FE the collision occurred takes damage. What we have in AH, intentional ramming is very hard and the player who could potentially have had access to the data to avoid it takes the damage.
Neither take damage. Leads to people flying through other aircraft, guns blazing, lack of concern about collisions being a pretty big distortion of air-to-air tactics.
Only the player on who's FE the collision did not occur takes damage. Rammer's wet dream as only the player could not have potentially had access to the data about the collision takes damage, rammer gets to ram over and over and over. Insane and obviously not a good idea.
It cannot be any other way given the limits of the internet.