Firstly best wishes to him for a speedy and full recovery. If he wants to, there should be something set up to allow fans to chip in for his legal costs because the only way the club are going to do anything is if there is a big bastard spotlight shone on their behaviour and it's impact. They don't care about us but they do care about reputational damage to their 'brand'. There should also be some sort of protest in the ground too. It's pathetic that it's got to the point that City fans need to resort to this but we know otherwise we'll be ignored.
I imagine for the club to be liable you have to show they have a duty of care, that it's been breached and that there's been material damage as a consequence. Hard to see how that's not the case here.
You'd like to think that at the point where their own fanbase crowdfunds an injured fan to take legal action against them they'd be shamed into sorting it out but somehow I doubt it.