Oh, I see. We’re going to do that.
I'm uncertain what you think I've done or what line you think I've crossed.
But that's illustrative of the point of this interaction we're discussing in the game. A thinks B has crossed a line while B is unaware that there was a line or that they crossed it. So, should the behavior of A be constrained by this or is it irrelevant. The point of the game is to emulate a real world, with real people who act and react in real ways. People with vast amounts of power use that power to stomp on "lesser people" every day. Ruining lives and often times ending them.
There is a difference between not having plot armor and not doing something in character to provoke nearly getting your PC killed.
Which Marisha did. She provoked a very powerful person by not kowtowing to him. She treated herself as his equal, which to most...if not all...very powerful people is the one unforgivable sin. She was warned, repeatedly, by both NPCs in the scene...and yet she persisted. There's nothing arbitrary about it. She had multiple opportunities to stop, but didn't. If that's how Marisha is going to play Murray in the schemer's group, she's going to need her backup character ASAP.
Ostensibly, this is still a game. Those were some hidden dragons. Marisha was bantering. I can’t think of anyone in a game situation who would’ve thought of that as perpetuating an attack, particularly when there is that big a power discrepancy.
Brennan's NPC clearly thought it was an affront worthy of death. If running that NPC in that situation, I can't say I do anything differently. Yes, it's still a game. But, importantly, it's a game about emulating a real world with real people living in it. If your 3rd-level character steps up to a dragon and taunts it, it's going to kill you. Simple as.
In any normal game, it would be considered unfair.
No. You consider it unfair. To me this is normal. To you it's clearly not. To the majority of OSR/NSR games, this is normal. This is how you run a living, breathing world.
Now, personally, I don’t think that the PCs don’t have some level of plot armor in the prologue. The gang heading to the tavern and nearly getting trounced by rogues sure seemed to have some level of plot armor as evidenced by the timely arrival of Vaelus. And while Teor was in trouble, my guess is he wouldn’t have died in that scene given some of the nature of gods and afterlife that we know so far. Critical Role is not a “normal game”. Critical Role is for entertainment, with players who know they need to perform for an audience, and the story needs certain beats to provide that entertainment. But as mentioned before, if someone were to do that in their own non-audience, non-actual play game, it would probably produce a different effect for the players; not one of joy.
But you do you.
The above only makes my point for me. It's entertainment first, game with friends a distant second...if it's on the list at all. So it follows the rules of all other entertainment, like say Game of Thrones. You wouldn't say any of the deaths in Game of Thrones were unfair...or you'd say all the deaths in Game of Thrones were unfair. I don't know. All's fair in love and war.
But, even considering all that, this is exactly the kind of verisimilitude that sparks joy in a large group of gamers. Myself included. Again the majority if not the whole of the OSR/NSR scenes want exactly this. Anyone who's interested in story over game would likely get a kick out of it. Etc.
You don't want it in your games. Big difference.