I never found out if he had attempted to seek out the lifeguard that had found it. Personally, if it had been my money I would have made sure to give the finder a reward.
Are you permitted to accept it? I understand tour guides aren't even permitted to accept tips...
DW lost her baseball hat on Splash Mountain on our second trip. Didn't know much about WDW L&F then and probably didn't want it back.
Lost a left child's pink croc at Epcot. DD#2 had a habit of kicking off one shoe while in the stroller, and not telling anyone. Didn't get that back but tried. They DID have a left child's pink croc of the right size - but when I showed up, it was a different design (when there was only like 3 designs), so apparently we weren't the only ones with this sort of problem
Same trip, she kicked off both her sandals at DHS. But we found out somewhat quickly, and I knew where I last knew she had them. Someone picked them up and placed them on top of a trash bin where they could be seen.
When I took DD#1 for Star Wars Weekends, she had bought herself a Jedi Mickey baseball cap. Before leaving to go home we were at Epcot, and went on Spaceship Earth. She took it off for the picture and left it on the seat. We left without it. Just before we got in the car she remembered, so we booked it back and talked to the CMs. They looked but didn't see it. I left our info at GR, and called the next day from home. They had it, and sent it to us for free. DD#1 was ecstatic as there wasn't much chance of getting another one.
We did leave a small bag at Tusker House on the last trip. We hadn't been gone more than 2 or 3 minutes before I realized it, so I ran back - and they had already taken it from the table and were in the process of sending it to the park L&F already! But our server caught it before it left.
Friend of mine we were with one trip left a backpack behind, twice, in the same day. The first time he got it back quick, the second time he had to go to pick it up.