The tricky task is to distinguish between those 3 cases - and to find general rules which can do this in every situation in a unique way, and represent your concept of morality at the same time.
If you can do this, publish it.
Well, yes, finding a simple description of morality is hard. But you seem to be asking if there's a possibility that it's in principle impossible to distinguish between these 3 cases for some situation -- and this is what you call a "true moral dilemma" -- and I don't see how the idea of that is coherent.
Here's the new thread for posting quotes, with the usual rules: