Meh...Tom can't hack two shits. My guess is either the mods accidentally gave him global mod powers when they meant to just give him board mod powers, or they gave it to him with full knowledge.
EDIT: I own one of these forums, and after checking things out, I think I know how it came about. It must have been that for some reason, changing the status of a user was granted to board mods(which is stupid), when its supposed to be granted only to admins and global mods. So, Tom, being the SOB that he is, changed his own status.