He did the same to some others. He is using that flimsy no alts rule to ban anyone that comes back from his legacy user bans.
At this point the spammer accounts are almsot certainly his. And he is using them to justify banniing new users thay he disagrees with.
Basically Dom has gone soft rogue and the forum is compromised.
He can IP ban users however. I know this because I spoke to one of the legacy users and who tried to return and got autobanned bedore posting anything.
He used a proxy and..everything was normal again.