A few things.
Squad cars don't prevent a round from penetrating through into a cabin. There is still plenty of windows and being stuck in your car is the worst place when someone has a gun pointed at you. Training across the world, whether for police, military and in some cases civilians is to keep moving. Especially if an active shooter scenario exists. You do not want to be a sitting duck.
As for shooting to kill. You are trained to stop the threat. Now that means targeting the greatest centre of mass, being the torso. The result often if they achieve this means death may and likely does occur, however try shooting an arm or a leg and miss. Bystanders are at risk, especially on a new York street at 4pm. Such a difficult shot to achieve.
As for Australian police. Training is to meet the threat with equal or greater force. Once the person gets rid of said weapon, you then reassess and if necessary disengage and urilise another option. Be it a baton, taser, pepper/ oc spray.
As I stated earlier, without knowing all the details it's unfair to speculate. However based on what I'm aware of at the moment I have no issues with this incident.
At the end of the day however when you turn up to this incident as a police officer and information provided is that a man is acting crazy with a guy threatening people and when you arrive he points it towards you in a shooting stance there isn't much time to decide is it real ? Will he fire ? Is this possibly an active shooter ? Suicide by cop, and if it is then you don't want to be waiting for him to shoot first.
Firstly all of the facts are out. The only thing that isn't is the verdict by the cops own internal investigation. From all of the eye witness and the statement from the chief in the press conference they know what happened and have even released cctv footage.
The Police in the US use their cars as a shield when in armed situations. That's a fact look it up. Its not just some Hollywood thing. It's their first line of defense. So regardless whether bullets penetrate it or not that's not the point. They had potential cover in the interim to assess the target.
Judging the fact that no shot was fired at their car as they drove up even though the guy was in a "stance" gives you an indication that it may be ok to use it.
Come off it they are trained to kill or neutralize. The wording on their training goes "two to centre mass" and if need be "one to the head". you say it yourself that will kill most people.
No one is asking them to pretend its a movie and shoot legs or arms but shooting someone dead right away is clearly not a good approach.
I have no idea what you are trying to say about the Australian police. They are clearly trained no to shoot first. They always pull their batons first, pepper spray or taser next then gun based on the situation so you are off. Look it up there are plenty of documentaries about how they teach cops.
Your last paragraph just contradicts your overall stance because clearly they did none of what you are mentioning as you yourself said they got out and fired because he was crazy and with a gun. That was based on eye witness reports i am guessing and not their own knowledge or assessment.
Ironically your last paragraph is what most of us want to happen. For them to properly assess the target and assess what they could do before firing their weapon.
What other options based on fact, experience and other events of similar nature.
None of that occurred here. four of them rocked up and opened fire with no words or no thought of talking or disabling him by any other means.