Bucknor has a history with Indian players and there is enough room to suspect stuff about him. Have made it clear why in a post in the official thread, can't be bothered to do it again here. Benson was just plain incompetent but his incompetence cost us more than Australia and is one of the main reasons Australia won.
Aussies are not exactly cheats in the sense that claiming such catches seems to happen everywhere, but when you make an agreement and then still claim such catches, your claims to playing fair will be questioned. Why is that a surprise, I cannot fathom...
And yes, it was obvious that the ball touched the ground. Watch the replay, watch Clarke's finger positions and where they are pointed and tell me how is it possible to take a clean catch when the ball is so low from that position? And leaving such circumstantial evidence aside, he quite obviously did ground the ball while rolling over and as such, by the law, it is not out. It is one thing to claim such catches when there are no agreements, but when an agreement is made, it assumes that the players will be fair and here, Clarke wasn't... End of story. As I said, to me Ponting appears the more honest sort and I tend to think he might have thought he was in control of the ball when he appealed for that Dhoni catch, but CLarke is just a different story.