I was under the impression that it was legal to carry on a hospital. In my recent sda class the instructor said that hospitals are on the prohibited list and illegal to carry in. Weird.
Your instructor was incorrect. Just one more example of people teaching these classes and "educating" others when they don't even know the material themselves. Pathetic. Your instructor should be forced to return your money as well as every dime he's ever taken from any other paying customer for his "training".
In Texas it is illegal to carry in a hospital but they still have to post proper signage and at EVERY entrance. In Oklahoma the only hospitals that would be illegal to carry in would be run by the feds (VA or military base), on a reservation that does not permit carry (most if not all of the reservations do not accept carry permits), or those on University grounds.
A lot of places want to place big scary signs in an effort to bluff those people who are easily fooled into submission. They think that the signs make an artificial safety zone which is true but only for the criminals who ignore the sign even if it had force of law.
This is exactly what it's about.... it's about making people afraid, when they know good and well there is no law against it. A sign on a hospital door in Oklahoma (other than V.A. and Indian Health facilities) carries no more weight than a sign on a convenience store or shopping mall. If you are seen with a weapon AND asked to leave AND you refuse then a peace officer MAY be summoned and you MAY receive a $250 fine for trespassing.
That's it.