Say you run a business. Someone posts false allegations about you. Do you:
1. Answer them, and risk: a) inflating the story and keeping it in the press, b) being treated negatively by many bloggers/internet pundits who don't believe you because you're a company vs. an individual, c) risk saying something that will later hurt you in court?
Or:
2. Listen to the advice of your lawyers, who tell you that it's best to keep silent?
If somebody makes a statement of fact saying a certain person sent him an email and gives exact strings from that email, merely saying "That was not in the text of my email" will hardly be a legal problem.
I would have agreed with you if the statement was a subjective one such as "The CEO of the company was being racist or was biased because of my gender". Refuting such a thing is hard and you may inadvertently say something that hurts you later but this is not such a case.
Also, she hasn't quite been silent. She clarified the amount due on this thread (unless you want me to believe that was a part of some grand conspiracy). A similar clarification on the content of the emails could have been made if that guy made those lines up.
