You can take precautions (rock solid agreements, protector/council) but if the worst does happen, it's time to involve courts. It won't be easy and it won't be cheap, but that is your recourse. Hopefully only courts in jurisdictions with sensible, effective legal systems are required.
The best remedy is prevention, though, insofar as it's possible.
You usually surrender control, but I frequently︂ see setups where the nominees let the UBO have direct access to accounts. It has︃ to be done carefully, since giving the UBO control can compromise the entire structure.
Another way is to have the nominees appoint a CFO that you know and trust to︄ (also) have access to the account.