Shop shutter hit me

Hi,

I was walking out of a shop yesterday  during my working hours and as I exited someone who was hanging around outside pulled the shutter down and it came down full force and hit me right on the head. I wasn't knocked out or anything, but about 5 mins later my left eye started to seem as though the vision was blurred. I have had a constant headache since, and last night started to slur my speech and forget what I was going to say etc. Called the GP for advice and they told me to go to A&E, which I did. I was waiting there for 3 hours, which was a right pain. They told me I had a concussion and just gave advice on not driving etc. Head's still sore now, still got a slight blur in my vision and feel a bit like being drunk or something.

My line manager called the shop simply to make them aware of what happened, that I had been injured at the shop, but she said the owner gave her a serious amount of verbal such as, "Are you threatening me?" and "What, are you phoning up to say I should apologise to him?" etc. I suspect that this will be a 'deny all' thing from this dude, who, from seeing him in the shop quite a few times before, seems like he's a bit of a dodgy, wheeler-dealer type.

Any ideas on if this is a claimable accident, or what would happen if I did go for a claim?

Thanks,
menv