It's not a good article, it's drivel. The only difference between this article and Hoopers argument is that Richardson's been paid to construct his factuous argument. It's the same spurious 'evidence' used and based entirely on presumption, not fact. It's been proven that Murali's action is legal, and ultra slow-motion does prove the legalitys of it, Richardson obviously just doesn't know what he's looking for.
In the slow motion clip I've seen, you can clearly see that what appears to be bending and straightening of the elbow on live full speed pictures, is action rotation of the shoulder and wrist, there's nowhere near 15 degrees of straightening. Also, as mentioned about a hundred times, Murali's also bowled with a brace on his arm, which stopped Murali from bending his elbow. He then managed to go through his full repetoire of deliveries, with ease, just using his wrist and shoulder rotation. He bowled in that experiment to Michael Slater with the brace on and brace off, and Slater said that it was exactly the same facing him with the brace on or with the brace off.