Got asked to describe a time I disagreed with a decision, gave a flat answer, and the interviewer's follow up question saved the whole thing

First answer to the disagreement question came out flat and diplomatic, basically 'we talked it through and found a middle ground,' which said nothing. Interviewer followed up asking what I actually believed was the wrong call and why. That follow up forced a real answer out of me and the rest of that round went noticeably better than the opening minute.