Thank you for the clarification.
Ok, so 12.9 prevails and I can’t extend my arms when covering a cutter. What about the case where I am marking the thrower, and a cutter runs through my arm? Does 12.4 prevail, because extending my arms is a legal position, when marking the thrower? Or maybe the case where I see the disk coming, extend my hand to block it, and the cutter runs through my arm to get it? Does the fact that I am trying to block the disk, instead of the cutter work in my favor?