Yes, but the author actually only tried once. Every other example he gives, he claims he hit refresh to get a new one instead of attempting it.
Also, I have to wonder if he was simply mistaken about that first attempt. Are we sure it didn't just fail because his username/password was wrong and display a new captcha, causing him to assume he had failed the first captcha?
I do have to admit most of those are cases where both words are difficult or impossible. But we can at least assume that the easier of the two (the one not cut in half) is the control in most of those.
I do have to admit most of those are cases where both words are difficult or impossible. But we can at least assume that the easier of the two (the one not cut in half) is the control in most of those.