When I have exactly one item in my List relation, it is directly shown in it. Isn’t showing “1 item” and then navigating to the list from it a more user acceptable behavior? I don’t know but the present behavior confuses me as a user when there is 1 item in the list relation (showing details and going directly to the details screen).
I suppose that’s up for interpretation. Some people might see that as a feature. I see what you are saying though. I assume you would rather not use an inline list?
Inline list or list relation makes sense based on one’s interpretation of functionality that is desired. I just prefer the List relation to behave the same irrespective of it has 1 item or more than one.