<p>This happened to me on the second semester Chem final. I didn’t want to get yelled at, so I didn’t tell him and just took it and got a perfect score. He made me re-take the audit of the same year exam.</p>
<p>What you did isn’t cheating at all, no more than if you happened to look at a specific text book page which covered the DBQ prompt. It’s his fault for using a publicly available prompt.</p>