I appreciate that you may be trying to look at this objectively, but my point is that the police officer will have to justify his use of force based upon the threat he felt there was. We could never really understand that threat from a couple of short clips, especially given I don’t believe we know yet why they approached one of the individuals in the first place which is a factor in itself. Other factors to consider will include that the officers were armed (I can’t imagine there are many circumstances that an armed police officer is attacked in training that doesn’t result in an attempt to take the weapon), the speed of the attack, unknown number of assailants (the video shows how many but did the police know at the time given they were being attacked from behind at the start), injuries to fellow officers, what was being said e.g. I’m going to kill you etc.