Probably not. But the bottom line is, if they don't like a teacher having a gun in their car, they can show em the door.
If you could prove thats why they were shown the door, that would be a a violation of the law and the SDA explicitly allows monetary compensation for violating our states 2A laws.
TITLE 21 § 1289.7a TRANSPORTING OR STORING FIREARMS IN LOCKED MOTOR VEHICLE ON PRIVATEPREMISES – PROHIBITION PROSCRIBED – LIABILITY ENFORCEMENTA. No person, property owner, tenant, employer, or business entity shall maintain, establish, or enforce any policy or rule that has the effect of prohibiting any person, except a convicted felon, from transporting and storing firearms or ammunition in a locked motor vehicle, or from transporting and storing firearms or ammunition locked in or locked to a motor vehicle on any property set aside for any motor vehicle. .C. An individual may bring a civil action to enforce this section. If a plaintiff prevails in a civil action related to the personnel manual against a person, property owner, tenant, employer or business for a violation of this section, the court shall award actual damages, enjoin further violations of this section, and award court costs and attorney fees to the prevailing plaintiff.D. As used in this section, “motor vehicle” means any automobile, truck, minivan, sports utility vehicle, motorcycle, motor scooter, and any other vehicle required to be registered under the Oklahoma Vehicle License and Registration Act.