It's always possible the cash was taken by one person and the the wallet was turned in by someone else.
Never mind possibly - it's more likely to have been what actually happened.
Handbag thieves ('wallet' and 'purse' you to Americans) will get away from the area as quickly as they can (public toilets are good), go through the bag they have stolen and take what they want/can sell and then dump everything else somewhere convenient as quickly as possible. Sometimes it can be in a trashcan, sometimes into a bush or over someone's garden wall/fence if they're in a street.
My parents used to leave their front door on the latch so you could just walk in - very useful when we were all living at home. However, one day they came out of the lounge where they were watching TV with the door closed to discover that my mum's handbag had gone. Some opportunist came into the hallway, tiptoed right through the hall and into the kitchen, took the bag and then got out again, all without my parents hearing a thing! They don't leave the door on the latch if there's just the two of them anymore, especially as they're getting on and are both a bit deaf.
Anyway, the day after reporting the theft to the police, the bag was found a couple of hundred yards down the street dumped in someone's garden with everything still there except the actual purse wth the money and CCs in.
I never hang my bag on a chair or put it on the floor. If I can't put it on the seat next to me I have a special hook thing which enables me to hang the bag from the table. At the very minimum, I put it right underneath the table between my feet and put my foot through the shoulder strap.
Staying at CBR this year the place was full of foreign cheerleaders or something, and the food hall was packed when we got to it. They all dissipated as we ate our dinner, but then there was a group of girls going round table-to-table, one of whom was in tears; turns out she'd left her iPod on the table and now it was missing! I advised them to ask one of the staff who were clearing tables in the first instance in case they'd picked it up for safekeeping when clearing the tables. But honestly! What is it with teens these days putting expensive iPods and phones etc down on the table in full view and then either taking their eyes off them or even walking away and leaving them there! Something like that can be pocketed by someone passing in the blink of an eye.
And just because it's Disney doesn't mean that theft can't and won't happen!