Slight correction: It seems he wasn't exactly fined for hiding his face. Police asked him to uncover his face and he told them to "piss off", for which he was fined.
You'll find in the UK that it's quite common practice to use the vagueness in the law to pin a different charge on somebody. Being rude to a police officer isn't a chargeable offense, yet it'll be treated as such. The police have no requirement or training available to actually understand the nuances of the law, nor are they updated when the law changes. The British police is mostly under-trained and under-funded, especially as you break out of the London bubble.
One of the major issues with UK law is it's vagueness and openness to interpretation, which is all of course by design. You don't tend to notice erosion until the ground beneath you collapses.
In the US you would just get charged with resisting arrest. This is what happens when they ask for your ID and you refuse to give it to them. You wont be convicted but the fact that you can be arrested for resisting arrest without committing any crime is a problem
Scenario 1: You get fined if you refuse to expose your face.
Scenario 2: You get fined if you refuse to expose your face, and are rude about it.
I don't see how scenario 2 is worse than scenario 1: it seems obviously less bad. Now, maybe in fact it's
Scenario 1: You get fined if you refuse to expose your face.
Scenario 3: You get fined if you're rude to the police.
This comparison is more debatable, but I still prefer 3 to 1, because not exposing your face is a thing that has (so to speak) possible functional uses, so if you can't do it then you've lost something that could actually be useful to you, whereas being rude to the police -- which, for the avoidance of doubt, I do think people should be free to do -- isn't really something anyone has a particular need to do.
Again, I can understand why someone might prefer 1 to 3. But if my civil liberties are going to be gratuitously eroded, I'd prefer to lose ones whose value is only symbolic.
Wait, that's not a slight correction, that's a whole different thing. So nobody was fined for covering their face, but when they swore at cops they got a fine for that? That's quite a distinction. That's the difference between being fined for speaking ill of Budha/Allah/God or for swearing at the police man who asked you to voluntarily not do that.
One of the major issues with UK law is it's vagueness and openness to interpretation, which is all of course by design. You don't tend to notice erosion until the ground beneath you collapses.