You de admined him after rejecting his idea for the thing HE built?
I understand that Major didn't react very maturely to the situation but he had a right to be angry. Technically, you stole HIS build first, if that's what I'm hearing. He built his own thing, there was an arguement over what the thing should be, and you tell Major that you want his build to be what you want it to be. Major saying his builds/servers were better was going a bit too far, but why did you just make it what Major wanted it to be in the first place so none of this crap happened?
Nonetheless you did use very good administrating skills to take care of the problem, so I congratulate you for being the better man.