You're assuming with no evidence that she was snitching on reformists and not simply rival revolutionaries. That can all change with specifics of who she was snitching on but I don't know where to find that information. It stands to reason though that mere reformists wouldn't get black bagged.

Saying "snitches get stitches" isn't deontological, it's inherited wisdom of centuries of consequences. It's not absolute, but it's too easy for someone to think they are the exception. Going around saying it's acceptable to snitch is how you end up with zero support from fellow proles and zero trust of your comrades.