erm, he should have taken the bribe to confirm it was actually a bribe and not just words in an email.... then take the moral ground back by dispersing the bribe for the greater good.
Or just returning the 10 BTC to original address. But it doesn't matter now. The matter is all open publicly.
I'm not aware of Havelock or AmHash scam, but from what I'm reading, I appreciate what OP did. Exposing malicious practices instead of accepting the bribe.