<p>You didn’t cheat. This happened at my school; our english midterm last year was literally just one of the AP Lang review books’ practice tests (5 Steps to a 5, I think). A bunch of people had been using that book and therefore had already seen in-depth answers to every question. Not cheating, just a great stroke of luck for them.</p>
<p>Also it’d be really unfair for them to say that you’re obligated to report everything that you hear or see.</p>