I have not gotten far enough with the game to try tanking a raid yet, so I don't know the specifics of the mechanics. I will say that I have played a number of MMOs with "stances" and toggles that generally stay on all the time even through logging in and logging out. Sometimes crap happens and stuff you think is activated is not, I can't see a game company actually taking action based on a toggle being off, regardless of how it works, or a raid being wiped. A lot of people are focusing on how that toggle works, but I have to look back at long years of playing and wonder why the company would notice, care, or intervene. If they considered not running the toggle to be griefing, then they would likely just make it so whatever it does a passive feature of the class that activates alongside going into combat mode.
If I had to make an educated guess I'd look at the attitude the OP has towards leaving groups, and saying "meh, I did my 30 minute leaver penalty". I did not see anything written about it here, but I know in some MMOs despite the penalty they tell you flat out that excessively dropping from instances or groups can get you in trouble. Usually though this is more tied towards people wanting to drop from instances early to speed up specific kinds of farming, leading to the game tracking a lot of partial instances "just in case someone theoretically came back". Corporations being sociopathic by their very nature setting their policy based on mechanical realities, rather than how it affects people at the end of the day. I don't know how this works in FF 14 but in theory if they have such a policy, and she's dropped a lot as the laid back attitude about it implies, it's possible she just finally dropped enough instances for some algorithm to catch her. Of course at the same time given the reason why companies usually care from what I've been told, it wouldn't have been a griefing complaint, it would have been specifically for too many drops.
Seems like whatever the truth is it comes down to a player complaint somewhere, and as they said, they won't violate the privacy policy... which is utterly maddening, and something that should be illegal for exactly these reasons.