What the original post calls trust is really a description of integrity. If you ask someone to honor their word by keeping a secret and they reveal it I would argue that the person who broke the promise has no integrity.
You trust a person of integrity. A person demonstrates a lack of integrity by breaking their promise to keep a secret. This creates mistrust or an expectation of future broken promises. The future expectation of a broken promise still means that you trust the person. It's just that now your trust is in the person to break a future promise vs. keep it.
It's a subtle difference but it's there.
