TWiT on Sunday speculated that this was probably more down to Hurd, like Carly Fiorina before him, failing to fit into the HP corporate culture, both were pushing for change in the company and wanted to bring the company into the 21st Century, a lot of the stalwarts of HP were against such radical modernisation and such a change in company culture. (Which begs the question, as to why they hired them in the first place.)
How much of this is him having done something greviously wrong, the woman has stated that she did not want this and that she had settled the matter with Hurd, and how much was the board looking for any excuse to get rid of him?

(She claims they never had a relationship and never had sex - although after Clinton managing to get Americans to believe that a blow-job isn't sex, I wonder what they actually did do...)