Well, spoken for truth.
But you highlight good points: the number of variables are infinite, but they all sort of point in the same direction. It's far more likely that you WILL have someone standing around like that on vacation, because what else is there to do? BUT... the risk is probably higher on vacay because no one knows that guy or even what state he's from because you have no way of tying it back. If you were in NYC, in an apartment building, it's probably less likely that someone is idling around in the lobby, but if there was, there are probably 20 people that know that guy and what floor/apartment he's in.