My unsolicited two cents:
Just to get it out in front, I'm not a big fan of Scott over here. Granted, he may at one point have (grudgingly) worked with certain members of the MAME team, and that's great. In the meantime, he seems to have done everything in his power to burn any accrued goodwill through actions like taking advantage of being on the MAMEdev mailing list (circa 2009) in order to outbid the rest of the team so as to ensure that the Vidkidz development systems would never, ever be dumped and preserved. It's pretty clear at this point that his value system is based on how many unique trinkets he acquires before he croaks, rather than any good works that will live on after he does, paying lip service to preservation from time to time by graciously sharing parts of his hoard with ostensible museums that care more about the value of selling tickets than any historical value. Not content to sit on his hoard, he now only pops up to drop drama bombs here and there, and to saw on the world's smallest violin about how very magnanimous he is to slum it with the folks at CAX with his precious Atari games. To paraphrase Ghostbusters, he seems to see preservation as some sort of dodge, or hustle.
In addition, I take issue with his characterization of this situation as "stealing". If this alleged malicious repairman literally absconded with the ROM chips themselves off the board, leaving a non-functional machine behind, then yeah, maybe I'd be inclined to agree. But what he alleges is simply by definition not theft in the eyes of the law, as there is no deprivation of goods. Last I checked, a person's ego isn't a tangible good.
Having said all that, none of this changes the fact that if what he alleges is true, the collector who was allegedly bilked has every right to be absolutely furious. A person's private goods, acquired through private transactions, are sacrosanct.
We can sit here and dither about moral imperatives as they pertain to preserving history, but at the end of the day these collectors either need to come around to the Kindergarten-level concept of sharing on their own, or they need to be left well alone. Forcing their hand, so to speak, is an incredibly bad look.
This isn't a fucking Indiana Jones movie. This alleged malicious repairman isn't Henry Fucking Jones Junior, swinging in on his whip to rescue the Ark of the Fucking Covenant from the clutches of evil. He's an asshole, and one that I'd be perfectly alright seeing thrown under what little legal bus there is to be thrown under. If we accept that what this alleged guy allegedly did is acceptable, what then? Why don't we just form a real Tear Gas Dumping Squad and start breaking into peoples' houses to wreck up the place? Shit, let's hire some black-hats to penetrate companies' networks to get all their data, if nobody cares about doing the right thing anymore. Where does it end?
At this point there's very little point in closing the barn door after the horse has bolted. With the whole SegaSonic Bros. fiasco, we've seen what happens when someone either erroneously or maliciously obfuscates the provenance of a ROM set in order to get it into MAME: Inevitably, bad actors make copies of the ROM set within seconds, and even if we pull support for it from MAME, the ROM set and associated driver code will forever be indelibly flung across the Internet.
This needs to stop happening. It's just not fucking right.