Firstly, he's convinced you that he's off-limits when he's really not.
Secondly, he's set in a motion controversy about himself which deflects from the original issue.
Thirdly, if he's got a few screws loose in the attic, or is as unintelligent as you might suggest, then all the more reason to disregard him. Yet, you attend to his nonsense and simplistic ideas anyway. If Victor's ideas lack common sense, then what's the big issue? Think about it this way: if you were to meet someone who was trying to convince you the sun revolved around the earth, and was unwilling to listen to reason, would you really blow that much steam if he didn't listen to you? I wouldn't. All the more reason to consider him a nut or a troll and move on. If you ask me, challenging nonsense as though your personal vitality is at stake strongly suggests some insecurity on your part, whether it be about the marrow of the topic you're discussing or something else entirely.