That wasn't just criticism, it was a serious effort at defamation. 7 online aliases, all from the same IP? yeah, someone was getting paid to libel the Dr. He was right to look into it.
But yes, I would still suggest when writing critical things about a particular procedure and doctor, that one use restraint and not resort to name-calling and excessive descriptions of a failed outcome.
eta: I've also found when reading reviews of normal things, like laptops, vacuum cleaners, etc that one *must* filter out the "pissy" reviews that were written by someone who doesn't know the meaning of the phrase "dispassionate review". One can always tell the more intelligent and reasoned authors by their tone and general reluctance to condemn and crucify.