Sorry Chris, I should have explained better but was rushing...
Didn't the WC conclude that LHO fired the shots with the rifle resting on top of a box which was itself resting on the window sill? If so, I struggle to reconcile that with the position that Shaneyfelt is contorting himself into to replicate the shots; the way he's holding the rifle shows a very steep downward angle for the shots compared to what would be achievable if resting the rifle on the box (actually, I think if the rifle were resting on the box, the shots would fly right over the plaza!).
Do the study take into account the angle of the rifle itself, not just the angle from the window sill (including the box)?
Perhaps it does and I'm just missing it...apologies...
As an aside, I wonder if the shots could be fired in the supposed time if firing from Shaneyfelt's position - it looks quite awkward to fire and reload etc.