I discovered a plot hole

So.....I'm reading year 2 again and came across a big plot hole at least for me.

In the unanimous vote special exam, they decided to give a protection point to Horikita in question 4 and in question 5 the school asked if they want to take 100 class points in exchange for someone getting expelled. Even if they didn't wanted to take that risk, those 100 points would be the easiest ones to get!!! They just had to nominate Horikita!! She had a protection point you idiots!! She wouldn't get expelled !! None of the rules mentioned that "you can't select someone with a protection point" or something like that! Not even Ayanokoji realized that!! Kinu just wanted to expell Airi to get rid of the Ichinose competition!! Ahhh that class is so ass!!