I know someone married to a police officer, who happens to have a connection with the shooter - so they claim. They were told a very similar story, and related it to me last. It closely matches what's in that tavernkeepers.com post with a few differences. And remember this is completely unsubstantiated and could be 100% bullshit, but I honestly have no reason not to trust this person if they heard from the person they said they did.
The person said there were three males that rushed the police car. They forced and held the door closed and attacked him through the window. They struck him in the face. When the officer managed to pull his gun out it went off. No mention that Michael or anyone else tried to wrestle it away from him. They began to run and the cop exited, told Michael to freeze. Michael turned around with his hands up and kept taunting the cop while walking towards him, saying "what you gonna do shoot me?" and such. The officer told him to stop several times and when Michael got too close he began shooting. No mention of anyone charging him once he was outside of the vehicle.