Agree
Wind doesn’t have a meaningful effect on the trajectory of a 5.56 at 200 yards or less. That is why in the Marine Corps, there is no dope change for wind at that distance— because any effect on the round from wind, would be less than the 1 Minute of Angle that the rifle’s sights are mechanically designed to move the strike of the round to compensate for wind. In other words, any manipulation of windage at 200 yards or closer, would overcompensate from the true zero.
He either had a poorly sighted rifle, or he anticipated the shot by pushing his shoulder forward into the stock, or both. Either way, a 150 yard shot from a prone position is ridiculously easy, even without a scope.
Now, if he had competition open sights of 1/4 Minutes of Angle, that's different. But he doesn't strike me as someone who would have them installed, or would even know the difference.