1. He was not the Vice President of the United States then. He is (and was then) a KPCB partner.
2. He was not the guest of honor, this was a dinner party at his apartment for the 10 people that could fit. Apparently he is fond of hosting dinners there and does many of them. At this event there were only two KPCB partners.
Is it a stretch to imagine that two out of all the partners at KPCB for this particular dinner might not include a female partner?
Also in Chien's testimony [2]:
Chien called the allegations in Pao’s lawsuit — including that he had declined to invite women to the Al Gore dinner because women “kill the buzz” — “hurtful and untrue,” and denied saying anything like that. Kleiner’s attorneys also showed multiple emails where Chien invited Pao to join meetings and business discussions she was interested in.
[1] http://www.law360.com/articles/625265/kleiner-partner-held-a...
[2] http://www.forbes.com/sites/ellenhuet/2015/02/25/kleiner-per...