Really confused
 

I am really confused. I finally got to play realistic (AMAZING! SOOO much better then arcade) but now when people crash, I sometimes get credit for the kill...other times I don't

This did not happen in arcade mode. If they crashed, no kill.

Example: Chasing a guy at ground level, right behind him I lay into him with three short bursts then have to break off, I watch him start to climb then go into a spin and crash "moozicmon killed ?"

Vs.

Chasing a guy in a climb, right in my sights I let one long steam of bullets right into his wing, he immediately goes into a spin, crashes and I see "? crashed"

If anyone could shed some light on this I would greatly appreciate it :)

It's a known bug, Anton said that it will be addressed, but it's a bit more complicated than it would seem. Just know in your heart that you shot them down, and all is well. ;)