Uh... no... no you really can't blame him for the fact that the stroke accentuated certain parts of his personality but that he otherwise was mentally capable in his brief periods of coherence following the stroke. The real problem was that nobody knew precisely how to deal with the issue, where the president was somewhat incapacitated but not fully so. Wilson was the person in some ways who would be the least aware of changes to his personality that the stroke caused to happen so it really takes a strong, strong dislike of Wilson to be willing to blame him for the mental issues brought on by his stroke.
I can blame him for acting as if he was fit even if he really wasn't. Same principle as faulting someone for running a race with a torn muscle.
Saying "Oh, I've had a stroke, but that doesn't mean anything." isn't an act of particularly good judgment.
If it isn't clear if he's okay or not, then he should know that (as in, that should be something someone told him).