I could provide endless commentary on this example, but suffice it to say, it is very difficult to look at this comparison and rationally argue no moderation bias exists. Now consider that this is just one tiny corner of the site. This is happening to millions of pages. Larry Sanger, Wikipedia co-founder, has been very vocal about its political bias. I, for one, believe him.
The article is so small, though, and on a topic unsympathetic to the largely white and male editor base, that flagrant original research doesn't register.
I had an experience a few years ago when a teenage girl was having consensual sex with me on a party in her room, but she didn’t like the sex, so she just casually told me that I have to put my clothes on fast and get out of the room (so that she can have sex with another guy), or else she goes to the police and tells them that I raped her. At that time I believed that it would be impossible to get me into prison for something I have not done, but the ease of how she said it scared me: the incentives against false reporting are clearly missing.