A friend from my Army days sent me a link to this article. I was an 05H which is Morse Code Intercept Operator. I had never considered Morse Code could be used this way, but why not! I think they were very clever!.
I'm surprised that someone this clever would be in a memory care facility in the first place. I mean, consider: he needed his long-term memory to know how to crack the code...and he needed a good short term memory to keep the code in mind whilst cracking it. So why is he in that facility?
He may have inconsistencies in regard to memory, many with Alzheimer's retain many of their memories from some of their lives yet may lose random chunks, also times of the day and different days may differ. Another issue may be the US healthcare system and the ridiculously small amount of time doctors actually spend talking to their patients.