This article provides more information.
http://www.thedenverchannel.com/new...for-not-shaking-superintendents_95850757

Quite frankly - if the child did not want to shake the hand of the people handing the certificates, why did he participate? Shaking hands is not assault - and as a mother, I would 1) never instruct my child (as it appears from the second article, she did) to be disrespectful at a public ceremony over a personal issue and 2) be very disappointed if my child perform what I consider a selfish act of "making a point" especially since this child was a valedictorian and presumed leader of his peers at a graduation ceremony, and shaking hands as the certificates are handed out is a part of the ceremony. It was not like he did not know (or the mother did not know) that shaking hands was a part of the process. And this is where I can see the influences of my parents, who did not grow up in the US but in cultures that values showing respect in situations like this such that I can not fathom this mother's behavior.