Shooting out the tires is something they do in the movies. In real life, shooting out the tires is very dangerous. Bullets tend to bounce off pavement and hit an unintended target.
By the way if they were worried about explosives why were they standing right by the car?
Because that's their job.
In retrospect, this situation could certainly have been handled better. But, given the propensity of our real enemies to use explosive laden vehicles as weapons, at that moment they had to make a decision, and the driver was acting like she was trying to do exactly that.
Your basis for that conclusion is pretty thin. It's the kind of militaristic paranoia that is used by police for an enormous number of what can only be described as atrocities in the name of "officer safety." As backup for my seemingly bald assertion, I suggest you read Rise of the Warrior Cop, by Radley Balko. The numbers are there.
“In real life, shooting out the tires is very dangerous. Bullets tend to bounce off pavement and hit an unintended target”
Have you ever read my tagline? Dude. I am still laughing.
Maybe they thought she had a light saber and the force was with her. :-)