They would have to bust the seller in order to legitimize the process. The gamble stores take when selling tickets to minors is they hope they don't hit the jackpot. They probably won't. The risk is all theirs. If the kid's ticket hits the jackpot, the state's not going to pay them out. the store gets busted. They're the only party that loses.
I can't believe how poorly regulated convenience stores are in California. They blatantly take advantage of tax breaks by calling their stores "delis", selling prepared meals along with alcohol, so they're not designated as liquor stores. Their 'deli' is basically having one or two prepared sandwiches in plastic wrap sitting in a refrigerated section that's blocked by boxes, and that have expiration dates from the '90s. Don't these places ever get audited?