Fair enough about shareholder obligations: I only have it on hearsay, from a business lecture as part of my CS course.

To try and understand your perspective further though: do you think it was ethically responsible for PlayHaven to fire their guy? Also, were it not for the DDoS, would the posts on twitter and comments have been sufficient to ethically fire her?

I find it difficult to rationalise how firing someone who's views and conduct are in opposition to the company - and who (as a PR employee) is bringing the company into disrepute is unethical.