TexasCHLforum.com

Keith B wrote:SB321 prohibits an employer, except a refinery or school, from making rules about you keeping a legally owned firearm in your locked vehicle. Your employer still has the right to prohibit you from removing the gun from the vehicle and carrying in the parking lot or building.

So, depending on exactly what the instructor was talking about, if he was referring to the building, then they were correct. If talking about IN your car in the parking lot, then they were incorrect.