I bet he is a bit shaken, I did a similar thing a few weeks back, nutted the girl and had the ambulance out. left me very very shaken with a damaged shoulder.
My lights aren't technically legal, and the rozzers didn't bat an eyelid. also I was riding fixed with only one brake calliper (yes, rear wheel is classed as a brake on fixed) but the rozzers didn't even mention it.
These peds who step out don't learn though. this morning on my way to work, the very same girl that I ploughed into did almost exactly the same thing, right in front of me.on the phone, wandered out into the road. thankfully my view was better this time and I had chance to slow right down and get out of her way as she sure as hell didn't see me.
Hope your son gets over the feeling of "what could I have done to avoid it?" and keeps on keeping on. and hope the lass is alright, of course!