It wasn't a slight bow obummer did. I've got no problem with a cheek kiss as that is a customary greeting in many countries while bowing is a sign of respect and to show you are lesser than the person receiving the bow. If both people bow, one will bow lower than the other.
The lesser individual bows the deepest and longest to show respect and lower social position.

He did get that right, as a person, obummer is a lesser man but since he somehow was elected the President of the United States, the office is not.