It actually is a sign of something terribly wrong with the company's culture. If a notoriously liberal company determined that complaints about "racially offensive" posts in this group were false, then one can reasonably believe that the complaints were indeed false. That means that other employees were simply lodging false complaints to interfere with this group's right to exist.
Think about that for a second. Other employees were so outraged by a tiny handful of their colleagues banding together to express mildly conservative views that they lied to the company about the content in this group in an attempt to eradicate them from existence. That is the opposite of tolerance, and it is reveals a toxic underbelly at a disturbingly powerful company. Everyone, regardless of political affiliation, should be concerned by that.