If these new revelations are correct, then your contention is wrong.
Taking the cop’s weapon puts the perp into assault to a police officer, regardless if the weapon is used. Once it is used it’s instantly turned into attempted murder of a police officer. Hot pursuit is to prevent the perpetrator from further assaults.
Can you guarantee that “Mr.” Scott would do no further harm? The cop did.
Bingo! Someone gets it. It’s about Slager’s reasonable perception of the situation, and if he truly believed Scott still had control of the taser, after he had already chased and fought with him over several hundred yards(and perhaps even had his own taser used against him), then he did not have the guilty mind that the lynch mob is howling about.