wrongly accused of plagiarism

<p>long story short, this may seem like your typical elementary school debacle, but my classmate had blatantly stolen my homework to copy right in front of the teacher. I, truthfully, had no say whatsoever. The next thing you know, i am accused for academic dishonesty and am given an N as a citizenship grade ( i still had an A in the class) Being the notoriously introverted person I am, I didn't speak up when i should have, and i totally regret it.
My mom had explained my situation to my teacher (which i should have done myself) and all i remember my mom saying after their conversation was that i should have spoken up. I don't know if that false accusation was permanently erased or not, so now i don't know whether i should, out of my morally pure instincts, mention this misdemeanor that never actually took place of my college apps. what should i do?</p>