I'm not an employee of playhaven, but I'm sure new employees sign employment agreements. Usually those agreements reference standards of conduct and that violations can result in termination. The court would have to establish that the employment agreement is null and void, which is a much harder challenge.
"I doubt his company had a sexual harassment policy that was substantially more aggressive than what the law provides."
What we don't know is if employees of playhaven complained about his banter. If they did, and he was informed and asked to stop, then it's his fault.
"He should be able to get defamation"
He might get defamation from her but not from PlayHaven.