One time, back in my playing days at DT, I didn't hear the whistle blow right at the snap for false start or something so I continued to just absolutely wallop the QB. I didn't get a penalty but the ref saying "we blew the whistle" was pretty "embarrassing".
NFL: Its December 08, last home game at Texas Stadium forever against Baltimore, Im there live and I will never ever forget Romo trying to throw a bomb to TO and instead he throws like a pop fly that nearly touched the roof right to no one but Ed Reed and he ran it back for a pretty good gain that set up Baltimore with some points. It was the dumbest thing Id ever seen in my entire life and I wont ever forget that moment. Or the back to back 75+ tds.... I was embarrassed to be a Cowboys fan and embarrassed for all the legends that night, and embarrassed to leave Texas Stadium like that.