Some of these stories such as the nuclear waste one came from stories from people who met him at Yale, and reported in the Yale campus tabloid Rumpus. Jordan Bass, an acquaintance seems to be the source for several of the outrageous ones which were told in the context of Bulldog Days, an official Yale event featuring illegal underage drinking for high school seniors that were accepted. It's pretty clear that most of what he said at this event, assuming he said it at all, was intended as a joke. After it got written up in the campus newspaper and people knew him for this it seems he continued with the joke during his time there since people obviously greatly enjoyed it.
http://www.newyorker.com/archive/2006/10/23/061023ta_talk_mc...
* taught tennis to Jerry Seinfeld and Harrison Ford
* a specialist in Chinese orthopedic massage
* the Dalai Lama wrote his college recommendation
* he is an action star
* he is an espionage expert
* he is a professional athlete
* he practices on the C.I.A. firing range
* he participates in martial-arts competitions in a secret system of tunnels underneath Woodstock, New York
* he competes at skiing competitions in Switzerland
* he worked for the Russian Mafia forging passports
* won two games in a tennis match against Pete Sampras
* founded a charity for troubled kids
* wrote a book called "Women’s Silent Tears: A Unique Gendered Perspective on the Holocaust"
* is a professional male model
* must register his hands as lethal weapons at airports
* is one of four people licensed to handle nuclear waste in the state of Connecticut
* has killed two dozen men in Tibetan gladiatorial contests
My take? He was an awesome guy.