OP specifically states this was a new M2, so it’s not possible unless he left it unlocked.
It might be possible if he never associated it with an Apple ID at all (literally the first thing the setup asks you to do, I’ve never tried not). Without an Apple ID though, you can’t update/upgrade the OS, download App Store software, use iCloud backup, iMessage, FaceTime, apple care, contact warranty support etc etc. And Mac is pretty good about bugging you to do this. So if he did this, saying just “I didn’t enable Find My” is a bit disingenuous.
So to be clear, you cannot reset a Mac without a login just because it does not have “find my” activated.
BTW, then he also admits “maybe I setup an iCloud account I don’t remember.” But his other linked article about this states “They presumably can see that my Apple ID is associated with it.” Ummm. If that’s the case, why doesn’t he recover the Apple ID first? So on closer inspection a lot of things don’t add up, other than the fault was almost certainly his.