Commonly during anime
shows characters will drop and their legs will stick in the air. These are known as face faults and are often expression of a quick shock to something as overwhelming stupidity
person 1- As far as i can see you dont know my name
person 2- well you are near sighted.
person 1 - *face faults*
A version of faceplanting, this version being the act of going from standing upright to having one's face planted on or in asphault without any intervening movement or time. This usually happens in anime, particularly after someone does something incredibly naieve or stupid.
Jim: You just went to the third level of stupid.
Bob: There are levels of stupid?
Jim: Yes, you blew right past facepalm
and went straight to facefault.