And HR, instead of addressing those points, refuting what would be wrong, and leading him to apologize if so, thus sending a powerful message about the existence of debate and rationale, recommended his firing, making him a martyr, and validating the part about the lack of dissent.
If this document stated 'I can't believe we don't talk about whether or not corpses feel it if you rape them.' You probably couldn't use that argument. Google decided what he said is fucked up and that he wasn't part of their society any longer. That type of dissent excluded him from their society and therefore no discussion is necessary. He is divergent and should be removed, just like someone who can't write code.