I think it arrogance. It looks like he trys to make world class saves out of shots he can just smother with a simple step to the left or right.
With the shot he messed up on he moves the other way to where the ball is going. Was he trying to pre-emt a deflection or giving him self room to do a camera save.
Would de gea ederson mendy Leno alisson etc have done that. Can't see it myself.
my take on this is it all comes down to poor fundamentals. His positioning and balance is poor and thus he makes the average save look extraordinary and it’s why his save % has been so low for so long.
add that to the poor mentality and decision making, you have a dreadful keeper and that’s what we have in JP