Haters gonna hate, that's how the Internet works, alas. I read the guy's comment and frankly I don't even get what his beef is; you at no point claimed this was documentation of a "complete restoration" and it's not like you sawsall'ed it open like the "What's Inside?" guy and just spread its guts out to gawk at. Doing a basic exploratory once-over and testing is what normal humans do when they receive something in unknown working condition, and while this dingus may be "old" and "rare" it's not like you started chiseling the Antikythera mechanism for crying out loud.
Obviously some basic caution is a good idea, like (if possible) isolating and testing the power supply before moving on to the main logic board, etc, but this is solid state TTL electronics, which frankly can be pretty darn robust if you don't zap them hard enough to let the smoke out. (And so what if you did, honestly? Yes, it'd suck, but a few hundred dollars at Unicorn Electronics and bridging a few zapped traces would be the price for that lesson... although I guess blowing up the state machine ROMs might suck if someone hasn't already dumped them.) Maybe this guy *did* just treat that PET and Wang he restored like they were precious archeological treasures from the moment he got them and didn't dare power on anything until he white-gloved every inch of them, but, sorry, that's an unreasonable expectation.
(Especially when it's obvious from the massive burn-in on that monitor and other aspects of the condition that this terminal was ridden very hard and put away very wet in its previous life and was essentially "garbage" by the time it was taken out of service. Maybe if it were the only ADM-1 left in existence you could play the "But it belongs in a museum!" game and b***h about how it doesn't belong in novice hands but, sorry, no.
The CHM has a nicer one already. History is safe even if you make a boo-boo with this one. And your goal is clearly to "play with" your things, not just stick them on a pedestal, so in my humble opinion you have one in exactly the right starting condition for that; it's already ruined so the only place it has to go is up! That describes most of my vintage computer collection, honestly, and I think I prefer it that way.)
So, yeah. I'm kind of curious if the guy is going to answer your request for more detail about exactly what you supposedly did wrong, but whether he does or not by all means feel free to ignore it.
FWIW, I do remember in a thread a while back about that SWTPC printer I gave you a little grief for just plugging-and-trying the cable that came connected to it to a PC parallel port, but I hope I made it clear why that very specific thing isn't a great idea. (Long and short being that DB-25 cables are the worst thing in the entire classic computing universe because unless you have the manual you have absolutely no idea what the pinout will be, even if the "function" matches, because it's the most overused connector EVAR.) I definitely didn't want to discourage you from experimenting with these things generally, it was meant as just an actionable "best practices" recommendation in the future.