No, air brakes are engaged with a strong spring, the air is used to release the brakes.
Frequently when a tractor-trailer rig parks you will hear a big "sigh" or "whoosh". That is the sound of the air releasing, allowing the springs to lock the wheels.
Big rigs have a significant air reservoir which stores compressed air. If they have an air starter, they have a very significant air reservoir.
If the truck went over while in motion, it is very possible that the driver got excited and left without setting the brakes.