I was guarding a cutter one point. During his in-cuts, I would try to stick with him as much as possible and kind of keep my left arm/hand up in front of him as I ran with him in (forcing flick, so I'm on his left side).
In my view, I was just trying to play hard defense. My arm was in front of his body as he cut in, although he could, and did, easily keep running.
So, in essence: my arm was not pushing this cutter, grabbing his jersey, or swinging against him. I just kept it in front of and up against him to help me get the best position while staying close (alongside) to my man.
Is having the arm in front of the player as you run alongside him, keeping up with him ..illegal territory? Can somebody weigh in here? I can totally understand if I couldn't keep up and he ran right into my arm, that it'll be a foul.