He was actually pretty clear that he didn't really know why he was fired. He surmised the feedback might have been a factor, but certainly wasn't as confident about it as you paint him to have been.

This is hardly some horrible accusation against reddit. If anything, as far as fired employees talking about former employers goes, this is downright tame and respectful.

Moreover, he actually didn't bring it up first -- he was asked about it and simply answered the question.