Agreeing with Steve again.
If out of the box, no intent is needed to INT. But, if he is in the box, then intent would be needed to make INT call. Such as, if the batter deliberately sticks his arm in the way but is still in the box. If it happened and it wasn't intentional, then I would have nothing. But, if he did it intentionally and it is very obvious, then it is INT(tough sell in many cases but possible and for me, it would have to be so obvious even a blind man could tell).