Bombed the "tell me about a conflict with a coworker" question because my honest answer felt too petty to say out loud

My real answer involved a coworker who took credit for something in a stand-up and I said nothing because it felt too small to make a thing of. Sitting in the interview, that felt like a bad story to tell — too minor, makes me look passive. So I panicked and made up something vaguer on the spot about "differing priorities" that had no actual resolution and clearly went nowhere. Afterward I realized the real story was actually fine, maybe even better, because it showed I could pick battles. Should've just told the true one instead of inventing a worse fake one under pressure.