It prevents me from claiming a frag for his death. I didn’t; I claimed a frag for dropping a stickybomb on him. His death merely triggered the effect.

His death caused you to gain a frag.

I don’t see why this is any different from, say, grabbing a stickybomb and then killing yourself. You can’t gain a frag from your own death.

(err, purportedly caused you to gain a frag. I maintain you actually didn’t gain one)

I don’t see why this is any different from, say, grabbing a stickybomb and then killing yourself

It’s not, really, and that should be fixed, but the syntax in the ruleset is what it is, and it’s clear that I get the frag for fobbing the bomb, not for the death itself.