None of us want to speak ill of a POW, and I do think there’s a sense in which an honorable POW is living a heroic life every day.
But we don’t believe collaborators are heroes, even if we do understand the difficulty they were experiencing.
Now, there’s no absolute proof that McCain was a collaborator, but we do have an unusual number of vets who speak ill of him.
I’ve never heard the same thing about Admiral Stockdale even when he was Ross Perot’s VP candidate and political enemies would have had reason to bad-mouth him.