There's something else: in much of the Caribbean, the age of consent is 16, not 18. IIRC Andrew used to holiday there a lot, so any sex may have, in fact, been legal.
Er... the lawsuit is filed in Florida.
Does Florida (or the US as a whole) have the same provision that British law now does: that anything that is a sexual offence here may be prosecuted here, wherever it was committed?
E2A: ALLEGEDly.