It's too stup*d to use your/their bitcointalk username or password at least, to register in any site especially on that forum. But to keep the participants safe I'd rather to keep the funds in a trusted escrow since the total funds are not just 100$, to begin with.
Right. Did he already respond about the escrow?
From what I have seen, he is planning on escrowing the money himself. I'm skeptical if he can even be trusted.

Also how did he the ICO forums owner decided to hire a bounty manager whose activity here in the forum is all about post about social media bounties for such a big campaign?
https://bitcointalk.org/index.php?action=profile;u=2157460;sa=showPosts;start=20