How could Shiz move and breathe after being beheaded?

The disturbing account of the death of Shiz was a source of ridicule by some early readers of the Book of Mormon, but accurately describes an attested neurological phenomenon. Both Coriantumr and his rival were exhausted (Ether 15:29-30). If Coriantumr’s blade strayed a little higher than he intended, passing through the base of the skull, at the level of the midbrain, this would have caused decerebrate rigidity. This neural reflexive action occurs when the upper brain stem is severed from the brain causing muscles in the arms and legs to contract and would have caused Shiz’s body to rise up on his hands before bleeding to death. Simultaneously, the respiratory reflexes, which are controlled by the lower brainstem would have briefly retracted and expanded as well. As blood poured into the trachea his rib cage would expand making the eerie sound of struggling for breath. This type of phenomenon was first reported in a medical journal in 1898, many years after the publication of the Book of Mormon.