If her problem with it was that some random other guy openly finding some random other girl attractive in her workplace "makes her feel unsafe", then that would be highly hypocritical, as she admits she was dating a coworker and that other coworkers knew this, which can only encourage others to think it's OK to make romantic advances to coworkers.

I mean, you can't have it both ways. If you think men and women should always without exception be only cold and businesslike towards each other in your workplace, then don't date a coworker. Isn't that obvious?