A mentally unstable man high on self-concocted drugs, swinging a sword at officers who asked him to give them his sword? Yeah that sounds believable. As for shooting him, as a police officer you gotta assume that any weapon brandished that looks real, is also real. Otherwise you are likely to get yourself and others killed. So these police officers are attacked by a man with a sword, who then turns and runs to potentially attack other nearby bystanders. Shooting him sounds justified to me, especially if you know what damage a weapon like that can do. I will link a video so you can educate yourself. It might help you from making dumbfuck statements in the future. Also actually reading the article helps alot.