This police officer is outmatched in hand to hand combat and could have been strangled to death if backup didn’t arrive. He is also lucky that the suspect wasn’t able to apply a more effective choke earlier, otherwise there would have been plenty of time to strangle unconscious and murder the officer.
This video demonstrates that guns are not a trump card and can potentially be overcome even by a person who is unarmed. It is also important to recognise that grappling skills in this specific situation represent the only way to survive.