He is not throwing the ball.
Afridi comes from an area in Pakistan called N.W.F.P (It's a state)
From there, a lot of Pathans are born. Pathans are generally exceptionally strong, and have their arms can do different things. (Like Shoaib Akhtar, although to my knowledge, he is not a Pathan.) Afridi can indeed put force into his upper and lower arm, to obtain that speed. In this manner, the arm is still straight, and cannot be considered chucking, although in one manner he is throwing the ball with his lower and upper arm. I repeat, this cannot be called chucking.
By the way, Warne does somewhatly of what Afridi does to get his massive spin. Remember the ball during The Ashes, it was a way wide ball, spun, and took Strauss's leg stump? He used the lower and upper arm, to obtain that spin. THIS IS NOT CHUCKING/THROWING. This is allowed, as the arm is straight.
(Ronny isn't going to respond to this post now

)