How do two people greet each other?

President Park Geun-hye and Bill Gates

Bill Gates apparently greeted  Park Geun-hye, the South Korean president with a handshake. Looks like two people having a greeting. 
Well it seems that is not what it was. It was seen as a sign of disrespect in South Korea. The picture of the meet-and-greet between the Microsoft founder and Ms Park on Monday was front page news across South Korea. 
As an American, in general, I see nothing wrong with this. 
BUT...........if I was head of a company looking for business in another country, I might have brushed up on my protocol. Mr Gates was in South Korea as chairman of the nuclear start-up TerraPower, promoting its project to develop a next-generation nuclear reactor.Maybe he should have started out a little better. Like they say, when in Rome, do as the Romans.....