Here is the gravity of his offense in South Carolina where he smoked the marijauna:
Possession of one ounce or less is punishable by up to 30 days in jail and a fine of $100 - $200 for a first offense.
In fact, he probably didn't even possess the pot, he simply smoked something that was there, was a crime even committed?
If this were Massachusetts; there would simply be a fine with no possibility of jail time.
Yes, despite my person feelings on Marijauna and Alcohol; I would give him a mulligan if I simply took into acccount the gravity of the crime measured by the State Law that he potentially broke.