Indeed, there are two distinct events. One event was the struggler for the Taser. The other complete separate one was the shooting. It was no more about a struggling for a taser at that point, but about some one condemned to death for running away.
You are more correct than you may know. In today’s legal standards, each and every round the officer fired, each blow delivered, each discharge from a taser and baton strike are supposed to be measured in their own merits. You can easily have a confrontation which starts legal and ends up with actions that are illegal.