Listen, I’m seeing that attempt as a win-win in their eyes. If nobody questioned it, and he got to vote , without it being reversed… and he’s won….. win for him.
If he lost, and nobody questioned it, but later caught it, he can claim “see? How easy it was to cast an illegal vote? I’m sure Terry McA has thousands of his minions that did this!”… a win for him.
Probably thought “what the hell. Let’s try it”