[sc_rufctr]

You can't judge that cops actions based on that video alone. You have to go to the house and stand in that room.
You also have to talk to the cops and the other people who were there.

The cop that pulled the trigger saw someone carrying an object in a threatening manner that reflected light.
It could have been a sword (most likely) or the barrel of a stainless steel shotgun (Less likely).

Either way he perceived it as a weapon and made a decision to fire while he was shouting the word "FREEZE".
The way he said the word FREEZE is important ~~~

The cop didn't say it clearly because IMHO he was assessing the situation and making a decision to fire or not to fire while he was trying to say it.