To sum it up, your argument seems to amount to "The Entity did it." In the real world, we call these "Goddidit" types of arguments. But before I get into that, let's talk about Occam's Razor. (As it applies within our universe first.)
Let's go back to what the Razor actually says: Any explanation of observed phenomena should make as few assumptions (and postulate as few hypothetical entities) as possible. This is often paraphrased as, "All things being equal, the simplest solution tends to be the best one." But why should this be? The best support from it (that I've seen, and in my opinion) comes from Jerrold Katz:
If a hypothesis, H, explains the same evidence as a hypothesis G, but does so by postulating more entities than G, then, other things being equal, the evidence has to bear greater weight in the case of H than in the case of G, and hence the amount of support it gives H is proportionately less than it gives G.
This means that if we have available to us a given set of evidence and two theories, G and H, H being more complicated, and both G and H explaining observed phenomena, then H, by nature of being more complex, is going to require more evidence to support it. Since we have a finite set of evidence, H will have proportionately less evidence for it (relative to how much it needs) than G. This means that G is better supported by the evidence, so G is the better theory.
Now, what happens when we're working with finding the laws for a
fictional world? We have to keep in mind that it was written by humans. If they have a significant imagination, they're going to want to show it off, and we'll see it in the world. If there's a consistent set of laws in this world, it's likely that the writer wouldn't intend it to be unnecessarily complicated, and would probably be imagining the simplest set of laws that explains everything that happens. Even if the writer comes up with a more complicated set than we do, if ours explains everything we see in the world, it's just as valid, seeing as we can't go in and compare them (if the writer writes more, things will change). Plus, our theory has the aesthetic benefit of being simpler, so we might as well go with it.
Okay, onto your argument. The problem with any type of Goddidit arguments is that they lack any predictive power. If we assume that some entity did something in any particular case, we lack a springboard to predict for future cases as we don't know if or how the entity will intervene in that case. If we have no other possible explanation for the events, this isn't such a big deal. But if we do have another explanation (as we do in this case), then it makes sense to use it, as it gives us something we can use for fan projects (fiction, Crimson Echoes, etc.) Of course, we'll never be able to definitively determine which actually happens, but the latter case helps us proceed a lot more.
