The police car seen in driving footage is different from the one seen parked. The word "POLICE" is seen on the moving car but is absent from the parked one.
Paula's parked getaway car from the school has two white vertical strips beneath the rear driver's side window. When the car is on the road, the strips are missing.
During the shootout from the classroom, it's nighttime. However, when the cops are shooting, it's daylight.