The human mind adapts, he only recently concluded that there is a difference... It doesn't mean he can't have visual humor. He just experiences it differently ( text/facts vs images)
I'm really skeptical of this "disorder." I think it mostly amounts to "semantics and variability in human abilities, not pathology."[1]
Metacognition like this is super slippery and is really easy to draw whatever conclusion you want. I've just never been able to draw even mildly realistic anything ever, this doesn't mean I have a disease.
[1] http://doc2doc.bmj.com/forums/open-clinical_psychiatry_aphan...
Sure, we can call that a "variability in human ability" rather than a "disorder". I never used the word "disorder" anyway.
And, I mean, you _did_ couch this as a disorder when you made the single-subject case study your proof.