You make an excellent point, and I debated whether I should call it one over the other, and I called it Weaver based upon the fact that it appeared one arm was dropped a bit more than the other, and I felt he had the recoil control, which comes about from the isometric push-pull or tension, which is the real hallmark of Weaver, as opposed to arm placement. That said, if you think it looks more like Isosceles, that is ok with me. Not argumentative at all. Good eye!

Best,

Shawn