OK, one at a time....
Sideboo, yes HE collided with you, you DID NOT collide with him. You would not have taken any damage from the collision, only his bullets. There are two "realities" in each encounter, yours, and the other guys. Due to lag, even mili seconds because nobody has a perfect connection, what you "see" is going to be different from what the other player "sees" If someone collides with you, the text is white, if you collide with someone else the text is yellow and you will take damage. There was gif of two films overlayed showing the same instance of a collision, if I can find it Ill post it here.
Neither of the other 2 films works. The AK one crashes the film viewer instantly, and the scothand one doesnt play and is labeled both mp4 and ahf

OK, the steady plane is just flying along. On his view/computer he see the pony to the far left, no where near colliding with him. The other guy view/computer is the middle pony that does collide so he is the only one to take damage.
That is how the collision system works and there is no way to fix it because it is impossible to have fast than light connection speed. So from your point of view, if you never run into another plane you will not take damage in a collision, that is how you can have control. If this system wasnt in place both planes would take damage even if like iin the picture you totally missed the other guy by a couple plane widths.