scratch offs must have a longer shelf life. When major prize are won the remainder need to be returned... Did People kept buying believing the $5M ticket was out there! ?
I don’t know. But most scratch offs games have an expiration date. Most state lotteries issue and run a scratch off game for a limited time period and after that particular game has ended, there is a time limit in which to claim the prize and 6 years seems way too long. Also IIRC, when a scratch off game ends, the retailer has to turn in the unsold tickets. All lottery tickets have unique serial numbers on them so that is how the lottery officials know how many winning tickets are unclaimed and publish how many winning tickets are unclaimed and publish the deadlines for claiming the prize.