The cop has responsibilities to all of the other citizens out there too. This lady had been observed as a reckless and dangerous driver and had committed assault with a deadly weapon almost running over the cop with her car. Everyone in her path was in danger. Officers have responsibilities to stop out of control people who have committed dangerous life threatening criminal acts before they injure or kill others.
After her continued and clearly visible mindset of total disregard for the safety and lives of others she had to be stopped. That was his job, his responsibility.
She was not the victim in this, she was the aggressive and callus perpetrator.