If he only First Blood RDMed once then +-0 but of he did it more than once +1
Bounce, when someone talks on the reports, we are hoping for proofs, witnesses, arguments about something who isn't clear at all, and pretty much anything that can be tough as useful.
But the thing is that saying +1 or -1 in reports doesn't help at all, since admins wont judge how many people agree or disagree with what the player did, he will judge his actions by the rules.
(note: If you think what the player did is debatable, you can feel free to post your opinion, but most of times this will be when you think the player shouldn't be banned or someones say he doesn't deserves the ban and you want to reply to that)