okay everyone who thinks is an unrealistic goal should stfu for a moment.
the view is from the bottom, while the crossbar is at 2,44m. we can assume that mizuki's upper body is between 1,6m and 2,0m above the ground while doing a regular side-volley kick. taking in account that he came running and jumping full-speed, it would be weirder if he did not jump high and attempted a side-volley.
and to those who think it might be called off:
nitobe clearly crossed the ball when mizuki was behind him. there is absolutely nothing that could possibly be called off