William's mace was sunken into the side of his neck.
Or rather, the grip of the mace - and the sword.
Under closer scrutiny, it was a part of the mechanism which shot out the blade - the small clasp which secured the blade to the grip, and which had protruded slightly, buried in his neck.
[…]
His body leaned further, and he fell onto the ground.
He wasn't dead.
Like being hit by the back side of a katana, he was knocked unconscious by the strike on the neck.

Toaru Majutsu no Index vol.18 ch.5 pt.9