I'm here to tell you that it doesn't matter. Talk about your tempest in a teapot. As far as I am concerned, Obama's quasi bow to the Saudi King is probably the result of the social awkwardness that has plagued his dealings with British royalty, the metaphorical equivalent of drinking from the finger bowl, a solecism I don't think he would commit.
In any case, of more concern is the concept of negotiations with Iran. Iranian leaders in the past have acknowledged that talks were just a means to buy time. Of more concern also are the apologies he's spouting, the policies he's enacting. Enough already with the bow.