Perhaps he can try changing his email address in h

Perhaps he can try changing his email address in his Settings. Then try the verification step. See if that works, and if so, change his email back to normal afterwards. Sounds like some sort of issue getting a verification message to that email address.

Another option is to create a new account with a slightly modified screen name and see if that works.

The truth is incontrovertible. Malice may attack it, ignorance may deride it, or a narcissistic board moderator may delete it because it doesn't support his disjointed thinking, but in the end, there it is.
   – Windbag Duckbill