I find things generally pan out better for everyone if I just let them go. This can appear spineless to some, but it's a big, strange old world and it can be full of surprises.
The Traffic Roid video was alarming in a way. Certainly, the driver was showing poor awareness and a selfish desire to make progress at the initial pedestrian crossing. There's no doubt it was poor driving. One sees that all the time; worse that, he drove on after another road user (Traffic Roid) had already stopped.
Worth noting, though, that the pedestrian was aware the car wasn't yielding and had not stepped out.
But... Roid then goes on a sort of verbal-vendetta crusade and embarrasses himself. I don't find his roadcraft great and he may have an issue or two. Engaging the patrons of a pavement cafe like a street preacher (and being ignored by all) is a worrying sign.
It's clear that it isn't Gaz in the vid; for all my wariness of HelmCammery, I find Gaz's clips are usually well presented, well argued and often very helpful. He is one of the excellent Helmet Cam brigade who wreck many of my prejudices..
Getting back to the original question, I still think it's often better to let it go. The shouter gets crosser, the original offender gets crosser... much adrealin is produced and either there's a fight or all that adrenalin just goes straight through the throttle pedal...
(Slightly OT digression: I spent a lot of time some years ago in S E Europe where at that time a culture of Gjakemarrje was still common. It's a strict social code of blood revenge. Very horrid, but it has some plus points. Nobody gets into silly, heated arguments in the street. It's not worth it; if you offend a man he has the right to swear blood against you and if it's agreed that you've offended him, that's it for you. There are strict rules to the matter, laid out hundreds of tears ago in a solemn text, but the end resiult is often a bloody death. It's a bit extreme and I couldn't live under it, but down where I was living there were no petty traffic disputes, probably because of that social code.)
I think everyone has their own red line. In my experience of many years in traffic and many years of having to talk to very cross people in fairly bloody ethnic conflicts, the more sang-froid you can muster, the better your chances of coming out smiling.
Also, it's worth noting that for many motorists a 'self-gratification artist' hand signal or a wave that looks a little like one is seen as provocation. I have no idea why some people have such thin skins, but they do. It's not just motorists...