Well, take a closer look at this guys, to determine who the really stupid people are.
Not the police: The guy was on private property and by law, if he is asked to leave by the property owner/person with such authority, and he refuses, he is guilty of criminal trespass. If he refuses to leave and the police arrive, they are obligated to uphold the law and arrest the offender. The circumstances of the trespass are moot, the guy broke the law not for wearing the shirt, but refusing to leave..
Not the judge: Since charges have not been brought, the judge could not dismiss, the most sensible/benevolent thing he could to was what he did: release the defendent OR.
The security guards: These guys are morons and showed poor judgement. It seems quite a reach to declare the shirt inflammatory. However, they DO have the legal authority to order someone off the premises, even if the reason is silly.
The man in the shirt: This guy is a lawyer, therefore he knew full well he was guilty of criminal trespass.
While this is silly, this sort of news reporting leads to irresponsible journalism for the following reason: When the prosecutor gets a hold of this, he will immediately dismiss, probably with prejudice. Comments will probably be made that the security guards were fools. THe news people won't bother to print the end result... its not "news worthy" . Buit in the mean time, short sited people run around saying or justice system is screwed up, while actually the system has nothing to do with what occurred here.
Of course, if the tresspassing attorney is female or any ethnic persuasion, look for a civil law suit to follow, claiming civil rights were being violated.