It seems to me that a piece of the court's reasoning on this, is that determining the actual level of liability in these matters requires a legislative, not judicial, action. The legislature can pass laws saying that church leaders have a duty (for instance) to warn congregants about child molesters, but not shop lifters.
I think this is what's behind the talk about setting a burdensome precedent. If the court decides that the WTBS is liable it has no way of stating where that liability ends. This would flood the courts with potential suits.
So, what we all need to do is petition our legislators to pass regulations regarding background checks etc for ALL adults who work with children.