Nah, he was fired for drawing negative attention to Google. Whether he was right or not is irrelevant; if you publicly criticise the company you work for, on a "controversial" topic, getting fired is the expected outcome.
You are assuming above that the guy that wrote the memo leaked it to the press. I suspect that we all write memos for our work places that could get us fired IF WE LEAKED IT to the press. However, I have seen no mention that the memo author was in fact the person that LEAKED IT. When will Google fire that person or persons?