The short answer, I think, is that
- the man is insured (hopefully) and
- the asset value of all the other planes he owns will be severely limited by the contract which he signed which prevents him just grabbing them back. His Trustee in Bankrupcy has no power to override that contract.
There are some other details which would come into play if this happened.
In practice, this kind of thing has not yet caused a problem, anywhere in the world, and N-reg trust ownership is dead common.
You can worry but there is always something one can worry about - this is why schools don't do adventure outings for the kids, and we have to wear yellow jackets for a 20 yard walk from the plane.
And my neighbour has a keylock on the heavy electrically operated cover on his swimming pool in case his neighbour's 8 year old kid decided to climb over a 6ft fence, managed to lift the heavy slatted cover, climbed under it and drowned himself despite all the odds
He got legal advice on this and as you might expect no lawyer would confirm he is safe from litigation no matter what he does.