I think, before joining a bounty, you have to research bounty manager well. You should read the texts in bitcointalk about the bounty manager. And especially if you sign up for a signature campaign, you should also research good the project.
I think He did all these. I am also on bountyhiveand I have experienced these things twice. I made videos for an ICO and I was not rewarded. This was due to low views on my videos. This is normal as a bounty hunter. The fact that, the project wasn't successful does not mean they intentionally came to scam, but as he said if the soft cap is not reached, it can't move on.