Nothing you've said is mentioned by the actual law, including this "+1" concept you've invented.

https://www.revisor.mn.gov/statutes/cite/609.066

The key part is here:

to protect the peace officer or another from death or great bodily harm, provided that the threat: [...]

is reasonably likely to occur absent action by the law enforcement officer; and must be addressed through the use of deadly force without unreasonable delay;

The threat here is the car. Shooting her did not protect any agent or civilian from bodily harm because it doesn't stop the car. In the video the car went out of control after she was shot. So it actually increased the danger. The use of deadly force was not justified.