Here is a lost wallet test. I'm not sure Australia would score this well, but I'd like to hope so.
After watching that video my thought was "but the person was right there in front of them, of course they would return it. What if they were long gone?" Coincidentally this video was posted within an hour of the wallet experiment.
Another good result.
Korea isn't crime free though and you should always be mindful of your surroundings and belongings. Hagwans (학원, also known as hagweon or hakwon) have a bad reputation for using dishonest tactics to rip off English teachers. I also just read about a foreigner who set up a business only to have his business details copied and used to defraud people out of money on a dodgy website. Generally speaking though, I've never felt unsafe in Korea and it is not uncommon to see a shops stock spilling out onto the footpath (a shop lifters delight) with no one standing guard.
To finish things off, here is a kpop (Korean pop) video about enforcing good social etiquette and being honest. FYI, the domed building he is standing in front of at the end is the Korean parliament house :).