I know it was because Grant got sick, I assume that is true, but it was a good move to have Zac be the spaghetti guy instead of grant. They all love Zac at dropout, he's everybody's friend. Grant is everybody's friend, but they would rip him apart on camera if it meant keeping him from spilling spaghetti on their podiums.
The meanest thing Sam ever did wasn't trapping people, or psychologically tormenting people, or continuously tricking people for the purpose of entertainment. No, the meanest thing he ever did was tear up Mike's, Ify's, and Siobhan's hand drawn pictures of ducks.