Question: this happened to a friend of mine, anyone hear of this happening to anyone else?

Friend is in an industrial accident that causes him to seriously overexert himself attempting to fix/get out; he ended up doing so much tissue damage to his muscles that he was breaking down muscle fibers into something that crystallizes in the presence of acid. These crystals thus trashed his kidneys, causing a total kidney failure that wasn't noticed for almost a week (he had all the symptoms of a stomach flu, apparently your kidneys won't let you swallow anything they don't think they can handle).
Fast forward several years, his kidneys recovered fully, he didn't even need long term dialysis. The doctors coundn't be sure whether or not there might be brain damage from the buildup of poisons from not having working kidneys for 5 days. The ONLY residual symptom is he can't sing patter-songs any more. He was very into Irish music and now just cannot keep up with the whackfolthediddles or tiddlyohtos. He still recalls all the words, and can sing the songs if he can sing them slowly, he just can't keep up with the recordings (or me).

??? Does this make sense to anyone? Anybody have any similar experiences, losing something musical while maintaining all other f-a-c-u-l-t-i-e-s intact, to quote Esmé with love and squalor?