Actions by people whether prompted by God or not, should be tried in the governmental justice system which is much less prone to corruption than ambiguous divine law. After reading about the Christos Valenti case, it is clear that the justice system, not one derived from God and religious views, is what we should use to try our criminals and exceptions as far as the divine law is concerned, should not exist. Having a law system inspired by religion is simply asking for corruption and is clearly not as just as the current justice system in the United States.
If we take into account what this seemingly good, innocent man did and make an exception for him there will be an outlet for all other criminals to use when on trial for something they know they will be convicted of. In all honesty there are enough loop holes in the law system as it is, and we don't need to make things any easier for murderers to get off the hook.
Let's face it; if you have money but did something which seems questionable (Kobe Bryant, OJ Simpson, Michael Jackson there is a good chance the charges against you will be dropped. The lack of an honor system that exists in our court today gives our criminals enough slack is. Giving criminals another possible outlet by allowing them to say that they were commanded by divine power could allow them to get an undeserved lesser charge. We already know that pleading insanity has proven to be a corrupt one. In particular, mafia members used to be trained as to how they could "fail" the tests and be considered insane thus reducing their sentence by as much as 60%. We also have charges like 1st degree and 2nd degree murder and even less specific things like "assisting" and so and so forth. The point is that the justice system has been set up to minimalize corruption. As soon as one considers divine law more just than US law, is when more corruption can occur. And if, in fact, the justice system is found to be unjust and an appeal is made, the law can be changed (ie Brown v. Board of Education and Roe v. Wade).
In addition to all these facts, the simple fact here that this is a highly unusual case should be considered. It is not every day or every year in which we hear about someone being a loving father murders one of his daughters in the name of God. Given these rare circumstances it shouldn't even be considered that an exception should be made. If this, or another similar situation, happened many times then a change in the law might be considered but in this case that completely out of line. This is an extreme unusual case dealing with the murder of a healthy young girl not a frog or even a dog. Once we make one exception in the legal system (which shouldn't by any means be made for this case) many more cases can be argued, for the door has been opened.
In the story about Valenti, his neighbors stated that once in a wile he would get drunk and they would hear him singing.