My apologies if the irony of the situation did not travel well to the USA.
Fortunately, UK ASDA/Wallmart appreciated the point the chap was trying to make. Now, rumour has it, they are even thinking about allowing "small" dogs in provided they are in a back-pack or somesuch. Just image the problems they are going to have deciding on what is a "small" dog. It could get like the arguments at airports over the dimensions and weights of carry-on luggage
Please be assured that was a truly one-off situation albeit part of an ongoing campaign to point out inconsistencies in the UK Disability Discrimination Act. We are talking about sight and hearing impaired people who come up against far, far more discrimination, than discrimination against their dogs, in their day-to-day lives. They have no wish to make matters worse for others, be they pet-dog owners with no disabilities or disabled people who have no dogs.
Rules change and occasionally change can be brought about - just needs a heads-up in the right quarters from time to time (in our experience).