During the Garden Festival or whatever it was when Squall and Rinoa have their dance, Squall is being a total one of us and hanging out on a wall drinking. Zell runs up to him and sticks out his hand as congratulations on them both passing the SeeD exam. Squall promptly just takes a sip of his drink and Zell gives up.

People not shaking Zell's hand is a bit of a running gag. I think either Zone or Watts did it too? And maybe one or two other people.