The naive mental model of how this works is that Apple is taking the files he ripped onto his hard drive, storing them in the cloud, and then streaming them ove

The naive mental model of how this works is that Apple is taking the files he ripped onto his hard drive, storing them in the cloud, and then streaming them over the internet to his other devices. As you say, this is effectively what happens most of the time. The quality and consistency is so high that nobody's going to notice a few flipped bits. But for a niche album - a semi-official bootleg of an obscure 70s prog rock band - it goes wrong more frequently. It can't find the original album, but finds one the algorithm it thinks is close enough, but is actually a studio recording of a tribute band.