In RL, I don't think there is just one flavor of 1-3-1 zones. Some teams like to trap out of this defense while others don't. I think one common case is that the "player under the basket" isn't really an insider defender exclusively -- he's also responsible for sliding out to each of the corners with the rotation of the ball.
One way to beat this defense is to swing the ball around or throw it over the zone from one corner to the other. This defender then will be out of position, leaving the man in the "weak side" corner open from a 3 pointer.