I'm not a lawyer, but I'm not sure that applies. Public and private venues are two different beasts.
Well, the case in question seemed to be a swimming pool, where presumably one pays an admission charge for entry, much like a cinema. The issue is that they have likened the camera to the pen and paintbrush, making it no different from someone who writes a report on the film they have just seen, or draws an illustration of their experience on canvas or paper. All three are now classed as "mediums of speech".
You could probably still get ejected from the cinema by it's owners, just as they can refuse entry to a film critic they feel is going to write a negative review. The problem is that they may not be able to go beyond this right to refuse admission and have the camera user detained and arrested as is the case now. In most cases, the filming is clandestine, so it's a matter of what happens on those occasions they get found out.
Curiously, here in the UK it is NOT actually illegal to take pictures or film anyone, and if you are doing so from a public place, there is nothing much that can be done by someone who doesn't like it unless they can demonstrate that the problem is something other than someone "just taking pictures". However, there is no overriding protection from a constitution, so there are some places where filming has been dealt with by separate laws, such as videoing the film in the cinema, which is dealt with by copyright law, and there is no "constitutional right" that will get in the way here in the UK.
In a private venue, such as a leisure centre, they can use terms of entry to ban filming in certain areas, but it's a civil matter, they can throw you out, but they can't confiscate your equipment or have you arrested unless again it's more than a case of "just taking pictures" which is covered by other legislation.
The error seems to have been the way the Texas law was drafted, and it has taken until now for some clever lawyer to spot the weakness and attack it. It seems it doesn't rely on the nature of the picture itself, but the thoughts and intents of the photographer when taking it. This can never be proven to a criminal degree of certainty, what is being used as "proof" seems to be an interpretation of what the photographer might be thinking based on the thoughts and desires of others, and convicting on the basis of what others think his thoughts and intentions were.
In the case, he was filming children in a pool, children who were properly clothed and in full view of the general public using that facility. No one got into trouble for being there and looking, he got into trouble because he was filming, and it was presumed he did so for a "sexual reason", making the filming "improper". The problem is that when it comes to art and freedom of expression, these cannot be defined by such conventions. Artists can get away with all sorts of works, some rather offensive in nature, but "it's art" they say, and pretty much anything goes. It seems that this formed the basis of the attack by his lawyer, and it worked.
I am not entirely sure how this would be dealt with here in the UK, other than that he would probably be at least questioned by the police, and probably banned by the operators of the pool involved from coming back. If any criminal case was to be made, it would be under the child pornography laws, which have been adapted to cover "images of children" in the context of the digital age. However, it wouldn't be so much the courts he would have to worry about, more likely the local community once they found out about it. Problem is, if he could show that he was genuinely an artist, and that it was part of a work of art, no further action would be taken.
I bet there are quite a few "professional photographers" who are probably using this "occupation" as a cover story in order to take liberties that would not be acceptable to the community were they to have a different occupation. Same goes for "model agents" too, many of whom will offer "free shoots" to young girls with no real intention of producing a portfoloio with a view to getting them modelling work.
We might have to be careful though, because we might end up having to get a "camera licence" in order to take snaps of anything, so that the public can be assured that anyone brandishing a camera within a mile of their kids playing in the park has been properly vetted by the police, and is not going to have "dark thoughts" as he peers through the viewfinder.