>>10752104"Shake anyone to witness" is what Breaking Points are there to simulate. Shaken is one of the main Conditions you get from Breaking Points, which you get pass or fail. So if you see something happen in a game and think that a PC would likely feel Guilty, Shaken, or Spooked then a Breaking Point should have happened. Just because Tiara suffered an extreme thing that caused a Breaking Point doesn't mean everything that causes them is of similar intensity. Breaking Points cover a really wide gamut of encounters. Chronicles of Darkness, the game not the line of games, uses a very basic version of Breaking Points but even then witnessing a violent supernatural murder is going to be a Breaking Point for most characters, and a pretty harsh one at that.
Hunter: The Vigil 2e does do things very differently on this front but they're not using those rules so it's not exactly relevant. Would still have been a Breaking Point under those systems but a lot of the specifics are different, I can get into it if you care.