At the end of the day, a bounty manager is just another bounty hunter most times, since they work for tokens and do not have better chances.
The fault lies entirely with the project team, the bounty manager can not be responsible for cheating the project team. Bounty manager just does his job.
You're right. A bounty manager is a hired worker who gets paid for his work. But the project managers are responsible for the success or failure of the project. If the project is scam the bounty manager also receives nothing, just like bounty hunters.