Is it true you can get hours for missing a hair cut or a class?
Don't know about a haircut, but unless things have drastically changed you will get hours for missing a class without authorization. A sprinting cadet in class uniform is likely trying to get to class before it ends in order to get reported late instead of absent.
My son was three minutes late for a class. The only time ever close to being late, and had a legitimate excuse, but never offered it. He was reported to his TAC and Platoon Leader (I think) by the professor. He didn't get hours, but got some form of inner company discipline. He didn't complain. Just was disappointed he didn't get to class in time.