Initially, I think 'Didn't Search First' was valid - the subject has been discussed before, and that discussion would have led him to the key document that I cited initially.
(In fact, the site quoted in the original post states that it is an implementation of the ideas given in that very article!)

I s'pose the point is that the rating applies to the post - not to the person?

But you are right - Wong has now confessed to his mistake and stated his intention to read the article.
That is certainly worthy of credit.