US employment law is very different to that in the UK too. It is much simpler for employers to fire staff.
to me it sounds like they're using a technicality to get away with it.
It goes back to what more or less everyone says - if your going to put it on the web, EVERYONE can (and will) read it. She is only doing this because she was caught, not because she believes in it.
I agree it is a technicality, quite a good one to be fair.