I wonder on what grounds he would have based a legal case ? The airport efficiently offered a suitable alternative chair as a result of the airline (not the airport) losing his own chair. It was not to his preferred design but presumably complied in full with the relevant standards. Luton Airport have now acquired 10 wheelchairs that he deems acceptable. What happens when the next user objects to the colour ?
I also herniated a disc some years ago and was offered surgery. The surgeon commented that it would fix itself in about the same timescale post op so I decided to take that route. In the case of the complainant, he opted for surgery and it went wrong. I have some sympathy for the bloke but there was no reason for him to behave like a ****. At least the floor got a good polish.