I love that the BBC
actually had a real news story about this. (In general, I've noticed they do a far better job of covering disability-related issues than any US media outlet including NPR.)
I'd become aware of the Muslim belief about dogs being unclean mostly and unfortunately through not infrequent encounters with Muslim cab drivers who refused to transport me and my guide dog. I managed to get to a point of having a civil conversation with one driver, which is how I learned the details, and through conversation with other Muslims I have also learned that not all of them treat it like such a big deal. (One Pakistani client I worked with at a previous job said, "I had dogs growing up. You just needed to wash before prayer.") So it was a combination of religious teaching and cultural factors.
And there was the encounter with a woman on the bus, who Pepper approached all wags and sniffs and who reacted quite vehemently. We had a rather heated exchange that turned into another useful conversation. She later apologized for her reaction and said that she could see that Pepper was clean and was doing blessed work, and I apologized for not paying closer attention to what Pepper was doing and for responding so harshly.
But I've heard guide dog handlers make disparaging remarks about intolerant Muslims, in ways that aren't any more tolerant.
So I'm happy for this young man and his dog, but I also hope this helps build a precedent and a bridge of greater understanding in general and on both sides.
(Now idly wonders how common guide dogs are in predominantly Muslim countries...)