I don't trust the bounty detective, they are offering a lot of bounty this year but I haven't seen any really successful projects, the prices of those tokens have fallen down so many times and the bounty hunter has only received few dollars from their work. And recently one of their bounty has become a scam that is Kingcasino
Most bounty hunters do not check the bounty allocation equivalent value in USD before joining that is why they tend to receive a small reward. Aside from that, the bounty managers do not limit participants since it is for the benefits of the project. More promoter = more exposure. Luckily, we have some Bounty managers that somehow look at the welfare of their participants by limiting the number of participating bounty hunters and opening their ears for communication.
With regards to a project turning scam, bounty managers have little means of knowing those stuff until the scamming happens. Though I believe they are partly responsible since they are the ones recruiting participants of the said bounty campaign and getting paid for it.