> If you see the flaw in the premise (it assumes no fraud) then the conclusion does not follow.

Right. Or he could've been grandfathered in.

But more basically: this is logically valid, but not logically sound. These are two different ways in which something may be "true" or "false", and in this format, it's not completely clear, soundness vs validity. Based on context clues like the absurd premise of pilots -> medical exam, I assumed validity, but it's still a weird format.