Eh there are whole communities of people who do stuff like this as a hobby. There's no particular reason not to believe it.

Yep. I sometimes do this with ads for the housing market here in the 30k inhabitants town. Track down a house where the ad shows some exterior but doesnt tell the exact address, only the town or district. It helps a lot having done some OSM Mapping in the past and it is actually fun.

Wasn't trying to suggest it's unbelievable or discredit the guy's ability to chase things down.

Merely raising the possibility that he could have gotten his information another way.

People who put up things like this often want them to get found.

Considering the post is on /r/geoguesser it's much more likely they're just really good at stuff like this.

Some people are just insane at that game.