Ethicist: It is morally right to reveal a secret only if one has a legal obligation to do so and will not harm oneself by doing so.
Principles
if = put it on the left / only if = put it on the right
morally right --> legal obligation and won't harm oneself
(we want the judgy term on the right, so contrapose)
~Legal obligation or → not morally right to reveal secret
Will harm oneself
promised not to reveal and → morally wrong revealing likely to harm others
Evaluate
We don't want to think of morally right / morally wrong as a binary. There is such a thing as amoral -- not having anything to do with morality.
Giving to charity is morally right. Stealing from charity is morally wrong. Laying down in a hammock is neither morally right nor morally wrong.
Usually, if we're provided with two rules, and one of them has an AND in the trigger, whereas the other one has an OR, the correct answer will make use of the OR rule. It's easier to trigger those rules, since you only need to establish one fact to trigger them. You can't trigger an AND rule unless you establish two facts.
Also, we usually had to contrapose in order to even see the OR rule properly, so they're rewarding us for doing the harder thing.
Goal
We never need to use both rules. When we look at an answer, we'll start by seeing what it's concluding. If it's saying "not morally right" we'll use Rule 1. If it's saying "morally wrong" we'll use rule 2.
If it says "morally right" or "not morally wrong", we'll immediately get rid of it, since our rules only allow us to derive "not morally right" or "morally wrong". (We can only use a rule to prove/conclude/derive the idea that's on the right hand side)