Can someone tell me why?

On Friday D was coming home from college on the bus when he got into a discussion with another college student (A - nothing to do with his name) over whether yet another student should sit down.

A: Sit down, will you
D: Maybe she doesn't want to sit down
A: Whoever said that can suck my d*ck
D (standing up to his 6' 2 height): Wanna say that again?
A grabs D up near the throat
D grabs A similarly ready to push him away, having the longer reach
A thumps D in the face, once
Queue stunned silence on the bus
A immediately realises the OTT of his actions and apologises

D makes it home with a badly bruised eye and cheek, a cracked lower middle tooth and a broken off leaving a third of the original length tooth.

(photos taken today, 2 days after.  On the top one yes that is more bruising between the eye and the ear.  The lower one shows the tooth after the temporary patch/rebuild - 2nd from right - now at two-thirds its original size)


The dental bill is likely to be £500 - £1000.  I think, as D is a full-time student, there'll be nothing to pay.  However, I'm wondering whether to send a copy of the paperwork to A and try to make him pay.

Some out there may think we're being soft by not involving the police but, and you KNOW how warped some of the police actions have become, we wonder whether D's "Wanna say that again?" comment may be construed as incitement.  Besides D is not interested in pursuing it.