She's a tough old school is PPRune.
Wouldn't this be a compo case, in which case the he has to prove his claim yada yada, or has he lost his medical and it would be insurer suing insurer.
I had a bulged disc once, came out of nowhere was just getting out of the car. I couldn't fly for thirty days.
I have some sympathy for this bloke, back injuries can be a real bastard, no visible symptoms but **** loads of pain.