He wasn't. But in this particular case he wasn't addressing their doctrine, but their hypocritical behavior and thoughts.
But He also infallibly knew and taught the truth. He also infallibly knew the hearts and souls of men. So when you find yourself infallible, go for it.
#1
When other posters cited the way Jesus treated the Pharisees, your response was: But in this particular case he wasn't addressing their doctrine, but their hypocritical behavior and thoughts.
To a Mormon, what is foundational doctrine if not authority. Please read Luke 20. Youll see that you cannot cleanly separate doctrine from behavior (even Mormons know this). In that chapter the Pharisees question the very source of authority Jesus operates under (20:2). Jesus goes on to tell them a parable about their violence toward the representative of the authority. Jesus was telling them that their very violence was rooted in the protection of the religious turfthe vineyardthat they claimed apart from the owner. The Pharisees knew that this indirect accusation by Jesus of being mass murderers was uttered against them (Luke 20:19).
Earlier, Jesus had cut into the Pharisees (literal meaning of sarcasm is to cut into): Woe unto you, lawyers! For ye have taken away the key of knowledge. (Luke 11:52). Jesus didnt just harp only on their hypocrisy & general behavior, but very specific behavior which had removed the key of knowledge. (Are you going to try to claim that the key of knowledge doesnt have anything to do with doctrine?)
Yet one more example: Please review John 8:31-55. As you read through that, note these words & concepts & tell me that as Jesus openly condemns the Pharisees, is he addressing more concepts related to doctrine, or behavior, or as I would claim, more doctrine but cant be separated from behavior?
Truth (John 8:31, 32, 40, 46 + 44 says dont abide in the truth);
no word in you (John 8:37); cant hear the word (8:43,47);
dont believe in me (John 8:45); dont know the Father (8:55); dont belong to God (8:47);
children of the devil (8:42,44);
bondage (8:33) vs. freedom (8:36)