A principle that changes according to whose name is attached was never much of a principle.

A rule that produces different answers depending on whose name is in it is not a rule but a preference with paperwork. Everyone recognizes this instantly in others and almost never in themselves, because the exceptions we make always come with reasons that feel substantive at the time. The reasons are real; they are just not the thing driving the verdict.

When you find yourself reaching a different conclusion about the same behavior from two different people, write down the distinguishing factor. If you cannot state it without referring to who they are, you have located a preference. That does not make you dishonest, only ordinary, and naming it is the whole of the remedy.