SO had the choice to 1) not remove someone for a violation that hadn't actually happened, and 2) give her a warning rather than surprise her with a firing, and

SO had the choice to 1) not remove someone for a violation that hadn't actually happened, and 2) give her a warning rather than surprise her with a firing, and 3) follow their own procedures for removing a moderator. And many other choices besides. Heck, they could even have had a discussion with her.