Bounties, in recent years, have changed a lot. It is totally impossible to be 100% sure as there are too many factors that we must control and we cannot, as it is out of our hands. That the Bounty Managers keep the tokens intended to pay the hunters is not a 100% reliable solution either, since the project "team" can make an exit scam, and those tokens would not have any value, as we have seen with Usogui for example.