I don't have merits to give anymore but I left him positive feedback
I suggest you to reconsider your feedback, I would say neutral feedback is more appropriate in this case. I'm not saying he's bad, but catching one cheater is still not deserved to be trusted.
Ask yourself, can a 5 months user who's doesn't have any financial deal can be trusted? feel free to disagree if you think I'm wrong.
Some members will try to do this, maybe in the altcoin bounty campaign we don't know but we should be aware of this now.
Altcoins bounty campaign already messed up and some managers are still accept negative trust accounts, not really worth to catch a cheater in bounty section.