See, Torres must have a thick skull because nothing seems to phase her...however, the bottom of the jaw is seldom as thick as the skull and its almost like a secret button...hit it and boom--everything goes to hell.
The KO "secret button" in the jaw has little to do with bone thickness.
Three nerves - the hypoglossal, vagus and glossopharyngeal - come together in a "pressure point" near the jaw where a blow can trigger a momentary "communication shutdown" between the brain and the rest of the body. A blow to the jaw can also temporarily affect blood flow to the brain in the carotid artery. Blood supply, nerve signals to the brain and jolting ("sloshing") of your brain inside the cranium following a blow have more to do with why "everything goes to hell" if your jaw gets hit just right (or wrong!) than bone thickness does.
The best protection against a KO apart from blocking or slipping the KO punch in the first place is strong neck muscles to help resist your head being "snapped" in a way that triggers the momentary "shutdown".