If someone threatens to sue me, I'll let everyone know.
I agree with you and think that anyone claiming to own the roms would have a very hard time proving it in court.
However, Cloanto says they would do just that:
" because we are licensees of multiple components from different parties, we are part of a chain of responsibilities, both contractual and determined by local jurisdictions, when it comes to information about unlicensed ROM and operating system files, or copies of Amiga Forever. When we receive reports about web sites which are claimed to provide such files, we are obliged by law and by contract to take some action. This could be a friendly informative email to the webmaster, which usually concludes the matter in an amicable and constructive way for all parties, or, more regrettably, it could escalate all the way to the ISP and to local computer crime authorities. When this happens, we consider this a failure, and we feel very badly about this."