How is it tainted by that alone? It’s almost certain that at least some of the patients he amputated actually needed amputation.

It doesn't automatically condemn him but it will probably trigger some kind of independent review of his cases. Better hope it's a perfect record.

Yeah if the comment just meant a review is warranted, great. But it’s not like separating personal desire and professional responsibility isn’t a routine part of just about every career. (Not saying this is equivalent to saying “that shirt looks great on you” when as a retail worker you think a customer looks ridiculous; but the analogy isn’t so far off that we should be shocked anyone would manage to have the fetish and still be a caring professional).