Several times lately I have thrown a grenade and watched it fly far away from me . . . only to spontaneously combust a few seconds later and be told I killed myself. I don't know if it's a bug or if the server thinks it bounced back at me but it's really annoying.
I swear i've thrown grenades over my friends yet i somehow die when the blast appears next to me, as if the grenade had got stuck to a friendly or something like that. It is as if there was disconnect between what you see and what data the server has.
This happens far too often.