There's tons of ways to verify the info besides seeing someone's face on the camera, theres license plates, you can identify clothing if you wanna go the covered face route, you can check multiple cameras in the area if they say they walked and didn't take a car, and those are just the obvious ways I personally can think of, so I imagine people whose actual job it is to investigate these things has other ways besides the obvious.

The lottery system isn't afraid to do an investigation to verify things it's literally their job, and the fact that not only the lotto winner, but also the convenience store it was sold from gets a cash prize. It's not that hard figure out who's lying about what based on how easily everyone involved would cooperate.

I guess you haven't heard of these cool new things called video cameras. Theyre these cool little things that record images of whats going on in gas stations and other establishments that allows them to check the timestamp info gathered from the ticket to be able to track down who bought it and when.

And luckily gas stations and other businesses no longer need to keep tons of video tapes or even their own hard drives because you can upload this neat video to the cloud to be reviewed later.

Not sure how you seem to be the only one unable to sus that out but there's your explanation

The lottery system is pretty extensive in itself, even tho cash purchases are the main way for lottery they still track it by the machine it was printed from, serial number, an individual number assigned to each ticket, and the bar code printed on each ticket. (I'm sure there's other ways I'm not privy to but these are the major ones I know)

And with every gas station now being able to load their feed up to the cloud instead of individual hard drives. It makes it easier to find out who purchased at ticket based on the info gathered from the ticket.