I've been TKed many times, and in fact i unlocked the 100 player kills by accidentally killing a friendly. just look closely and hope.
I've been shot down by team mates *cough*Robotic Pope*cough* as a B-17 when im the ONLY B-17 in the CTA match.... i think people just want to shoot it down cus its still a rare-ish plane for those that didn't boost to get it.
just look for the red / blue paint scheme and use the map to identify the concentration of red dots.
and if you dont get one, get a HD TV, otherwise you wont see jack.
Good luck mate.