Respectfully perhaps we are missing the point here.

The post was about a .577 missing the brain, not about a shot in line with the brain failing to reach the brain.
For all we know it entered the skull, traversed it and exited at such an angle that nothing vital was hit.
Now I am sure the Ele' had a hell of a headache but that is just not a killing shot.

It would matter not one wit what caliber was used if it just drilled a hole in a honeycomb skull, I cannot see penetration as the issue just shot placment. A glancing blow to the head will not stop anything or anyone.

Regards