Saves it in your car. If you bring it to the service center they'll be able to pull it up in the logs.
And chances are they will not understand anything. They will just see that it braked . But to what? does it save minutes worth of video footage along with it? I don't think so! Without video it would be useless.
It could maybe solve things like wrong speed limits or things like that.
Tesla should be more transparent about how data should be reported and how that works.
To hear that tesla vision cars also phantom brake breaks my heart LOL. They should really have all hands on deck to fix existing issues that we who paid for it all experience every day, instead of 100% focusing on something that many of us that bought FSD will not experience in maybe 3-5 years.