I am not sure why anyone is surprised by this. Google does their best to release updates they think impact only sites they want to impact. But nothing is perfect and Google knows that. Whenever Google does an update, Google tweaks the update after collecting data where the algorithms potentially went wrong and this is no different.
"We deeply care about the people who are generating high-quality content sites, which are the key to a healthy web ecosystem," Singhal said.
"Therefore any time a good site gets a lower ranking or falsely gets caught by our algorithm - and that does happen once in a while even though all of our testing shows this change was very accurate - we make a note of it and go back the next day to work harder to bring it closer to 100 percent."
"That's exactly what we are going to do, and our engineers are working as we speak building a new layer on top of this algorithm to make it even more accurate than it is," Singhal said.
As I said originally, "I suspect Google will continue to refine it based on feedback they get. Collateral damage is always part of this game."
So if you were hit by this, I'd suggest you let Google know by posting in the Google Webmaster Help forums. Google will use that data, amongst other examples, to tweak this content farm algorithm. Not only will it give Google more examples, it will give you some emotional support. As of right now, we have just under 200 responses to our were you impacted by the farmer update poll - so take the poll, so we can get more data.