My gut instinct is that this guy doesn't have much of a chance to collect a dime.  Sony lawyers ought to be able to squash him like a bug.  I'm sure, for example, that the contestant release covers ANY injury suffered while taping, regardless of how it happened.  Proving that these particular injuries were the result of this particular five-second event three years ago will be tricky too.
Also, since when does Sajak spontaneously leap into a contestant's arms without reason?  Especially since he LOST the bonus puzzle?  That doesn't sound like something the notoriously laid-back host would do.