I think you missed the part where this was mostly one guy, evading their ban by re-registering new accounts. So it looks like dang was very ban-happy to just one of the sides, but it was one guy.
Apart from the multiple bans of one guy, I see comments from both sides of the argument getting called out about their tone.
And of course, we'd never know if the people who aren't banned would stoop to the foul crime of ban evasion. As they used to say, the law in its majesty commands that neither the rich man nor the poor sleep under the bridge.
Moreover, I was describing a general pattern of discourse, not just this one thread. If you don't feel you see this pattern, there's not much to argue about...
And of course, it is not just the mods. Downvoting polite discourse for content is something some people feel a social responsibility to do. We certainly can't avoid the consequences of the secular growth in this popular sense of responsibility.