Because he said "wait, damn you"? Shanks had to stop him to impale Momo in the scene after that one.
But it seems that if Aramaki says "wait" he is bagging, if he says he is going to impale Momo and Shanks has to intervene to stop him then he is bluffing and his words are not to be trusted.
But my first post was just for saying that in OP everyone makes stupid faces one time or another.
Kaido made another withe-eyed face against the very first Luffy with Ryuo, and Kaido was still enormously stronger than him. Oda likes that faces, I think.