Absolutely. I am also a believer in the perfect punch... I think if hit hard enough in the right spot, anyone can go out.
I just looked in my cabinet and all of my drinking Glasses are made in the UK. :rofl Glass Jaws exist in Boxing and we WILL discuss them on here.
It's hard to imagine a man like Calzaghe can have such a solid jaw in comparison to the glass sported by the likes of Broner and Eric Crumble. It's one of the great mystery's of the human body.