As the title says, it would be great if the "Killed" event could return a 3rd parameter which contains the <b>unit</b> that made the fatal shot.
The problem with the 2nd parameter, which indicates the <b>object</b> which made the kill, is that when the killer is inside a vehicle turret, it returns the <b>vehicle</b> it's inside of, and not the <b>unit</b> itself.
So, there is currently no simple way to find out which <b>unit</b> pulled the trigger, if the said unit is in a vehicle.
It is possible to find out if it was the gunner of a vehicle by analysing the data provided by the HandleDamage event, tracing back the projectile to a turret magazine of the returned vehicle, but that is way overcomplicated, and it does not work for the Ghost Hawk, which has 2 identical turrets that shoot the same ammo.
This is a problematic issue for missions that have custom scoreboards or teamkill management systems.
For example, with the Ghost Hawk, if there are both left-door and right-door gunners inside, if the right gunner kills a teammate, it will penalize the left-door gunner for it, because there is simply no way to know which one of the 2 killed the teammate, from a scripting perspective.