I think that third man may have been the wisest of the three because he's made the camels move. They must have left in a rush as they have left some evidence as to how they were persuaded.
A sneaky look across at the stable shows that there is, at last, a shepherd to keep an eye on those sheep and other animals. He's got a nice fire to keep him warm. In fact maybe he's a bit sleepy as he doesn't seem to have noticed the angels on the roof.