If you’re interested in the news you can read it here: https://toronto.ctvnews.ca/ontario-man-can-t-collect-lottery-prize-after-he-forgets-where-he-bought-ticket-1.6924708
I think it can be verified on the ticket itself where it was bought, that's a lot of pressure from a person who purchased the ticket to provide full information. Unlike here in my place when you won a certain lottery then there's no hassle you can claim your price instantly if the ticket is legit and authentic. The only problem here is that he been delayed in claiming the price because it's already been 6 months, that's why there's always a lot of requirements. Unless if attempt of claims will be done in a short period of time I guess it won't take a problem on verification.