Here's the deal - Controller's step in and balance all kinds of stuff if no one is around, or trained, to balance/reconcile accounts. It's a thankless task, based on the fact that auditors come around and criticize Contollers for being too hands on, e.g. separation of duties comes into play. Both the Controller and the Auditors are correctly performing their duties, but in the real world, stuff happens that just needs to be taken care of by the Controllers of this world.
Yes, you are correct, loan types should balance their accounts on a daily basis in a perfect world. In addition, sometimes Controllers go south, so they should not be the only one's reconciling stuff - a good certification plan had better be in place to support this scenario.