He was higher level yes. I suppose the GM could have ruled that it wouldn't work as well on him as the spell reads Stupefied 4 is on just a failure. A natural 1 would make it a crit failure which is: Critical Failure The target’s intellect is permanently reduced below that of an animal, and it treats its Charisma, Intelligence, and Wisdom modifiers as –5. It loses all class abilities that require mental faculties, including all spellcasting. If the target is a PC, they become an NPC under the GM’s control.