I don’t know how exatly it’s working, but it happened to me a few times now. I guess it’s when someone boards your vehicle and throws a grenade in it, and at the same time you blow your own vehicle up by shooting a wall. When you kill the enemy and noone else shot you, like the same thing when you throw a grenade in a vehicle then die before it explodes, then someone else gets the kill. You kill the person that boarded you, destroy your vehicle, but you just end up standing on top of your vehicle and survived.
It feels like you just blow yourself out of your vehicle.
I don’t know what vehicles are effected by this (only happened to me in Wraiths, but I think it works in a scorpion too)
As an example: