[not2b]

While I don't have a source, it seems clear that with sufficient training data they could do better at avoiding this mistake. This should not be hard.

[exporectomy]

Perfect accuracy in image classification is an unsolved problem. So yea, it's hard.

[SilverRed]

If Google and Facebook have both failed with the billions they have spent on the problem, I think we can say yes, it is that hard.

Obviously the people at google had thought of having more training data.