Fair criticism; I never really ran the wizard as a combat obstacle, only as a social encounter who locked the party in the cellar and ran away when they smashed open the trapdoor (he's less of a battle mage in my mind and more of a deranged scientist). If you want to go the combat route and have him "defeatable", the mage statblock would probably be a much better fit. Or, hey, use an apprentice statblock. The dude captured a child to experiment on, he's not necessarily strong.
So, yeah, totally fair. Don't know if I thought more than two seconds about that stat reference. Sorry ^^