It's not "just because he has a major medical condition". It's "because he has a major medical condition that interferes with his ability to assess the relevant choice".
The man literally cannot form new memories. How could we say that he could change his mind about something in a meaningful way? All the life experiences, reasoned arguments, etc. that are supposed to lead to people rationally changing their minds do not work on H.M.
Look, people end up mentally crippled in all sorts of ways, and we are forced all the time to ask the question "Is he so crippled that we cannot trust this new version? Or is the impairment minor enough that this new version is better representation than a third party mental model?" This question is unavoidable because there are extremes that make it clearly "yes" in some circumstances and clearly "no" in others. We have the "real, actual, living patient" in front of us all the time, and often they are profoundly disabled.
The man literally cannot form new memories. How could we say that he could change his mind about something in a meaningful way? All the life experiences, reasoned arguments, etc. that are supposed to lead to people rationally changing their minds do not work on H.M.
Look, people end up mentally crippled in all sorts of ways, and we are forced all the time to ask the question "Is he so crippled that we cannot trust this new version? Or is the impairment minor enough that this new version is better representation than a third party mental model?" This question is unavoidable because there are extremes that make it clearly "yes" in some circumstances and clearly "no" in others. We have the "real, actual, living patient" in front of us all the time, and often they are profoundly disabled.