Most people took a little bit of time to get familiar with smartphone UIs, especially for someone who's jumping from no smart phone at all to the latest version of iOS and Android. I wonder if he has been slowly learning how to use a smartphone like the other condition, or if he has to rediscover the UI every time.
I believe the memory used to retain skills is separate from other types of memory. There was a famous patient, Henry Molaison[0] who was the first person to suffer this condition and participated in some really amazing research. He was able to learn new skills, albeit slowly.
"His ability to form long-term procedural memories was intact; thus he could, for example, learn new motor skills, despite not being able to remember learning them."
