So Orwellian it's trite to say it's Orwellian.

That is an interesting point. The consequences of having the ability to do so.
This is where it becomes more nuanced and complex.
If the person shouting fire causes immediate mayhem and injury, they may face consequences but that would be after the damage is done.
The issue is to try to stop it happening in the first place.
If the person shouting ‘fire’ in a darkened crowded theatre say they have the ‘right’ to do so, so therefore it is kind of OK, they may be using the notion of rights to validate a wrong. The case for exercising restraint gets into conflict with the notion of ‘rights’.
Now it may be moral or religious forces that enable people to act in a decent way, or upbringing or education, or even fear, but whatever it is, something happens that causes most of us to put restraint before ‘rights’.
It might be ‘natural’ to cause the mayhem ‘for a laugh’ somebody might claim, because they say they have a right to ‘free speech’.