A thing which I've realized recently, is that since the "xxx collided into you" message was introduced, it appears that a lot of the HO deaths are actually collision deaths.
This one time, I've had a P-38 HO my Bf109G-10. I took the challenge, and landed the 30mm on his cockpit and moved out of the way in the nick of time... when suddenly, boom! I'm back in the tower... and the message, "xxx has collided with you"..
Normally, if this happened before, I'd probably be assuming that I lost the HO and maybe my pilot got shot before I've completely moved away... when actually, it was the enemy plane colliding into me which killed me.