You could apply the same logic if he had pulled his pistol and blown her brains out. In this case I think the cop failed to use the discretion that we've a right to expect from those to whom we assign such powers.
He wasn’t intentionally trying to kill her or punish her. He was doing his job trying to bring her to justice.
“Doctors say Danielle, who was found to have cocaine and oxycodone in her system at the time...”
she fled, high on drugs, cuffed, if he didn’t taze her and she ran in front of a car, would that be his fault too?
She ran out into the street cuffed on drugs. She already had a hit and run, 2 in fact. Eventually she would kill herself or somebody else. The law is there to protect the public from this sort of person.