It happens. Back about 84' I took my mother and my two sisters and two brother in laws to NYC the week before Christmas. Found a parking spot about 3 or 4 blocks from Rockefeller Center. We went to see the big tree and have dinner at the restaurant next to the ice rink.
Check came for the meal and I reached for my wallet...guess what wallet wasn't there? Panic...one of my sister's picked up the tab. Lost my License, American Express Card, Visa and $90 CASH.
Replaced the License and the cards within a few days.
Following week I get a call from Manhattan PD...someone found the wallet near where I parked the car. Turned it in...the PD had cut up the License and Credit Cards. The $90 CASH was still in the wallet.
Tried to find the person who turned it in...no luck. Was going to give him the $90 just for being an honest soul.
NYC...who would have thought...it happens.

I have had that happen a couple of times but the self-checkout worker saw this happen before I left. I'm sure this is common and returning the money is a sort of incentive to continue shopping at the store.

Reminds me of the time we were outside a convenience store on a side street in Rome. A woman came running out with a wallet and asked if we had seen the lady it belonged to. We said 'she went that way' but by then she was lost in the crowd.
The woman ran off looking for the lady and they came back together a minute later -- a cashier and a very grateful tourist.

People were always telling us to watch our bags because there were lots of thieves. I made a habit of wearing an empty bag over my shoulder figuring if somebody grabbed it that's what I wanted them to take.

One time on a bus an Italian commuter tried to tell me that I was wearing my bag wrong. I tried to tell him it was an empty decoy.
I don't speak Italian and he apparently didn't speak English so we must have put on a show. Finally he grabbed the bag's strap and pulled it over my head.

The only time we got robbed in Italy was by the Italian government. The instructions were confusing so we got on a train without getting our tickets validated and got fined 60 Euros.

The picture is me at the Campo de' Fiori market -- wearing the bag the way the commuter wanted me to. Ha, ha.

The self check out stations I use always have an attentive person overseeing the stations with a watchful eye and a helpful attitude. Glad it is so at your store too!