I don't think that the A-series bolt's striker shroud would have made any difference in this case. The shroud protects against gas coming back through the firing pin hole inside of the bolt and expelled rearward from the rear of the bolt. This occurs primarily when a primer is pierced. The gas from a case failure like was experience here is, fortunately, sealed off from the firing pin opening by the intact primer. Rather, the gas goes into the lug raceways, the LH one being vented through the action ring, and the RH one of which is blocked by the bolt guide. It is the existence of this bolt guide which keeps the dislodged extractor from being flung rearward (and perhaps into the face of the shooter) and also diverts most of the gas from coming directly back at the shooter. Remington 700 actions converted to use a Sako extractor have no such bolt guide and thus subject the shooter to significant hazard if a case failure like this one occurs.