IOC tried to send a letter to Paul Hamm suggesting he should give up his gold medal as the "ultimate demonstration of fair play."
The USOC refused to deliver the letter to Hamm, saying that Paul should not have to bear the burden of correcting the IOC's mistakes.
Based on the fact that the tape reveals that Yang actually made some errors in his routine that were not deducted, I think the issue should be closed. I don't think it is fair to pressure Paul Hamm to do something that he should not have to do. It's not fair: if he doesn't give it back, he looks like the bad guy and "unsportsmanlike." If he does give it back, he is the "fall guy."
It's really a no-win situation. What a shame.