Because he's good at building? (Common sense) Collin didn't give him BuildTeam for no reason. Don't ask. It's whitelisted. Only Mithrintia, Staff and the BuildTeam are allowed there.
Don't mean to necro post, but yes, you don't get any extra perms than what you were before. If you don't donate, you have the same perms as a normal player. All you get is the prefix and whitelist to the build team server. But we get to know all of the secret stuff before all yall do :>