Ok...so a bunch of people go to a meeting... its long and long winded. They send a few flirtatious texts throughout the week while sitting through the mind numbing speakers. She thinks its harmless but he thinks its real. One evening the team gets together and heads to Nonamebar and sucks down some wine and more texting occurs. She gets that loving feeling and texts her honey at home some suggestive comments. OK...the point is that she should not have been texting the AST. She has sexually explicit texts on her phone to her sweetie and doesn't want to those divulged. 
But if she really had a case to make against this AST, he deserved that she divulge her part in the story...that she had been texting him throughout the week and he took it seriously. Its not her fault...but it could happen. Show the whole story and get to the real bottom of things.