They murdered him for not wearing a mask
The greatest evils are always committed in the name of the greatest good.
Yes, you just watched a group of men assassinate another man. For the crime of not wearing a mask.
To what end?
To this end: to show you that the murderer and his accomplices were possessed by egregores. That is to say, they were willfully enforcing collectively-ingrained ideas. The murderer believed himself to be acting in the name of good. Nobody around him tried to stop him, which indicates that they at least agreed, or didn't care about the victim dying. All of them agreed that failing to walk around with a mask was offensive enough to merit being beaten to death. No bystander disagreed enough to intervene.
You see, perverse ideas eat human souls, then wear their skins — like meat costumes — in order to act, to spread, and to prevail.
In this case, the malevolent ideas were (1) the idea that not wearing a cloth on your face is morally evil, plus (2) the idea that violence in the name of imposing idea #1 is itself good. These are the two egregores that, in actuality, perpetrated and justified this cold-blooded murder. The two key factors, moral motive and moral cover, as always, hand in hand at any time a great evil is perpetrated, ready to draw diabolical epicycles. Satanic epicycles that take you from "because public health" to "let's steal all of a man's health until he is dead".
Mind you, none of these murderers came up with the idea that killing a non-mask-wearer would be a-okay — they were told so. Exactly like you have undoubtedly been told too, over the many months of the COVID panic. Dear reader: do you not feel even a little bit of the usual scorn, the hate, the contempt, for those who refuse to wear a mask? That was all programmed into you — the egregores have already begun to eat you from the inside.
This is not an isolated incident, and it will become more frequent as time goes. Anyone with two neurons to rub understands memetic trajectory well enough that, eventually, the egregores devour enough of the population that they begin to feel satisfaction, perhaps even cheer, when people are violated in this way. You can already see hints of this in your surroundings, when you hear acquaintances talk about "covidiots" and "penis masks" — both derogatory terms straight from the egregores, intended to dehumanize the target. So when evil people come to harm you, those around you might not say "I'm sorry you were violated" — they might just say you had it coming.
Perhaps you have objections?
Maybe you think you are innocent of soul, and say "well, I could never do this". Don't think that for a second. You can bet all your worldly possessions that none of the perpetrators and accomplices thought they could do it too... right until they were cordycepted into becoming murderous monsters by the ideas that motivated them. Maybe you can resist the egregores better than others — if so, good for you, but if the egregores wear you like a meat sack, you will do as they say.
Maybe you are already corrupt, but cowardly enough not to take matters in your own hands, thinking instead "well, it's fine if others — cops, perhaps — do that on my behalf". Then you are no less malevolent than the bystanders who watched this murder happen, and either did nothing, or collaborated in a minor way. All you are, is more cowardly.
Maybe you say, "well, that's wrong, but a fine would be okay". How, exactly, do you think fines are enforced? Then read the previous sentence again. If you are okay with a fine, you are okay with you or someone else beating a man to death or using as much violence to get him to submit. Which is exactly what the monsters in the video did.
Maybe you dispute the veracity of the murder video? That's not a problem at all — there are plenty of news stories about similar incidents (archive) so you won't get away with shoving your head in the sand on a technicality. It's worthy of note that the incident linked here proves to a greater extent how evil these ideas are, by a simple fact: there was a bribe involved after the murder with the goal of concealing it; the bribe clearly signals that the murderers knew they had done something evil — yet they still did it anyway. The egregores wear your skin, make you do evil, and then always leave you, to deal with the consequences of the evil you did in their name.
Perhaps you agree — perhaps you are one of the minority that doesn't agree people should be punished for not wearing a mask. You are in my camp then — the camp of people who do not agree with coercively imposing medical measures on anyone without their informed and voluntary consent.
Perhaps a semblance of sanity will return, and the mask murderers, their collaborators, and their cheerleaders, will be abandoned by the egregores that have them vomiting hate to perfectly innocent, healthy, sensible human being — and, in some cases, murderous violence against them.
A man can hope.