Some good points Targan. Perhaps because .50 BMG has such a thick jacket and doesn't deform actually improved his chances in a roundabout way, straight through with a nice clean hole at either side, less damage than if the round tumbled, a classic case of overpenetration
As for hydrostatic shock, it's such a murky concept I think it needs a whole lot more research done before I am totally convinced of either
1. it causes damage significant enough to cause death
2. it doesn't cause enough damage to warrant its inclusion as a factor in the stopping and/or killing power of a round.
Having started my training with the L1A1 and then later the F88 and having shot a few animals with .308 and .223, I'm leaning more towards big'n'slow will screw you up and fast'n'light will annoy you (there's a reason individual flechette rounds for rifles were discontinued). I think that hydrostatic shock while definately causing some wounding effect, tends to be overestimated in those effects