This was in response to religious hypocrites like the temple scribes and Pharisees (spiritually sick people in denial) asking why he was attending to repentant sinners (spiritually sick people actually going to him for healing); "Well if you're so healthy you don't need a doctor then, do you?"
A vigilante hero applying lethal force to a serial murderer who is in the process of trying to kill him at the time (however ineffectively) is not at all the same situation.
This was in response to religious hypocrites like the temple scribes and Pharisees (spiritually sick
