That's the problem with personality traits; they vary throughout a person's life, change following life events (of which a life-saving operation would be one) and are not easily defined through any empirical means. In other words, it is easy for somebody to subjectively state that there is a significant personality change in another person which may (or may not) reflect another's personality. To make it even more difficult, the 'pre' personality is often deceased, and aspects of their personality are inferred second or third hand.
Where does that leave us? With a subjective, emotional observation. Nothing substantial. Take that a step further; which would require the greater evidence - personality change resulting from a major life-event which, on occasion, may be selectively associated with donor personality traits...
or...
Lamarckian-like environmental influences can be encoded on a cellular level through a means as yet undetected.
We would need great reasons to even consider the latter, of which we currently have none. And not for lack of looking. Biochemistry is not a new science, and while we might not know the precise functions of all chemicals within a cell, there is currently no reason to infer a degree of 'environmental encoding' that would be required for a personality trait to be conferred.
It would take some pretty extraordinary evidence to swing opinions on that. Of course, if anybody has that evidence, I'd be happy to be the first to look at it.
Athon