Why do you think the owner's insurance company won't
come after you for the money they paid to the owner?

Because in the real world, they don't do that.

Over the years I've talked to several FBO owners, insurance agents,
and airplane owners who have been in situations where subrogation
would seemingly be justified, even called for, and the insurance
company has always declined to pursue it.

One aviation insurance agent I know has never had a policy he's sold
to go into subrogation (and he's been doing it a long time), and he
and his customers are actually quite mad about it because in some of
the cases the people the insurers declined to subrogate were
stunningly stupid and/or negligent and they thought very strongly that
they should have been subrogated, but weren't.

Subrogation is "out there" as a threat, but it's very seldom used in
the real world, if ever. It usually isn't worth it to the insurance
company. That is probably why you can't buy high-dollar renter
policies -- the companies that sell them know better than to sell
policies worth enough to make their customers attractive targets for
subrogation.

Can anyone name a specific instance where they know subrogation was
done? I've not been able to find anyone, and I've asked FBOs, owners,
insurance agents, etc, over several years. Does that mean you should
count on it not being done? No. But it's not the big boogeyman some
people are making it out to be, unless perhaps ou have a very high
personal net worth or some other unusual circumstance that makes you a
particularly attractive target.