The free version "distributed by the developers" was uploaded to to torrent site and made to look like an illegal version, so no one downloading it then believed they were getting a developer sanctioned version of the game.
And the blog post "Falsely slandering" people is actually wonderfully moderate. The dev specifically say they have no quarrel with people who literally cannot afford the game or otherwise can't legitimatly aquire it. They even admit to having downloaded games themselves illegally. The post focused on pointing out that for a small developer the choice to pirate a game has real consequences. It was more of a guilt trip than an attempt at slander.
They weren't mocking the people asking for help with piracy, they were saddened by it, although they did acknowledge the delicious irony of people who believed they were playing a pirated version of a game lamenting the loss of revenue caused by pirates.
They message behind the move was simple and profound; if you want good independent to continue being made show developers its a viable option by supporting games you like. The dark future outlined in the post about online only social games squeezing you for dollars and cents every few minutes, becuase its the only way to get people to pay for a game, isn't that far away.