It took people 7 pages to discuss this, over the course of 14 hours. The officers in the situation had seconds to make a decision, based on what little information they had.
It's always nice and lovely for the general public to hash over the details from the court case and say they should have done this or that. But the police don't have that luxury. They are NOT thinking "oh he's a piece of shit, I'll shoot him and save us the money of a court case". But if they make the wrong decision, other lives could be at risk. No matter what they do, people will complain. So they have to make a decision - THATFAST. And then live with it.