HPD is actually right. This section of penal code 30.06 reads; (e) It is an exception to the application of this section that the property on which the license holder carries a handgun is owned or leased by a governmental entity and is not a premises or other place on which the license holder is prohibited from carrying the handgun under Section 46.03 or 46.035.
The problem comes when some entity like the city of Austin rents out Zilker park for a “music festival” and the operator puts up 30.06 signs. This section of the law protects the CHL holder from being arrested. EXCEPT when LEO’s try to enforce “house rules”. And then the LEO and entity get sued for an unlawful arrest. I think if gun shows want to stay on public property, they’ll have to rely on something other than the 30.06 sign.
I’ve always had a problem with police working on their off time as security guards and competing with private security businesses using taxpayer funded uniforms, firearms, police cars, radios, and having police arrest powers. This is unfair to local businesses, and is a conflict of interest. After all, who will a cop who makes a lot of extra money working for a business man side with, when there is a legal problem between that business and another citizen.