Earlier quoted context omitted.
I upvoted your comment. Calling someone you work with and barely know a milf is an asinine move. That said though - she might have led him on when she agreed to move the conversation to whatsapp.
According to what was told, they moved the conversation to Whatsapp before he asked her to hang out. What would she be leading him on about?
One can argue that by agreeing to move the convo to whatsapp she sent a "sure let's have a private conversation" message.