Presenting an engagement ring is based on a promise to marry. If the date of marriage was after a divorce, which it must be, and the divorce is final except for 90 day wait, then the divorce has to be presumed certain and the promise to marry is still valid.
Most likely, this guy will win on appeal, if he can afford the lawyer's fees.
I would ass ume that his CURRENT WIFE will make sure of it... (so that SHE GETS THE RING (before starting divorce proceedings herself!!!).
Ah but what kind of a married man is sooo stupid that he gives his girlfriend a $40 000 engagement ring, but doesn't trust her enough to tell her that he's still married?
Didn't he ever hear of CubicZirconium?
;-)