But that would most likely be an expensive and ultimately pointless exercise, as for such an action to have anything other than a "moral" victory, the copyright holder would have to prove that financial loss had occurred as a result of the infringement. As far as I know there had been no loss.
That's my understanding of the law anyway. I'll happily be corrected.
Interesting update to MAME site this year:
http://mamedev.org/?p=405
I personally believe the wider issue was more than the MAME threat...
If he did have to release all his code, besides that of the MAME source, then I'm sure that certain manufacturers might have taken an interest into what other tools he used to create the emulator.
I believe MAME was just an excuse, and the smaller fry, in this so long circle of boredom - the real reason, I have always believed, is that whatever other coding he used, might have triggered alarm bells with the manufacturers of slots who created them in the first place...
There - more fuel to the fire of the burning remnants of FME! lol