He’s lucky all they did was cut off his entry permission.
How can they deny him admission if he’s registered and paid his admission fee?
He may be prohibited from bringing in recording devices and even pen and paper but where the heck do they get to prohibit him as an observer purely because of his profession, religion, or political affiliation?
If it was a Baptist convention being held in the civic convention center and some writers for a homosexual newspaper/magazine wanted to enter, you can bet there would be outcry of “discrimination” if they were barred entry.