If we’re expected to get to work on time, managers should be expected to let us clock out on time.

I'm working at Mcdonalds and I am always clocking in right at 8:00am, but two of the managers consistently leave me waiting 8-10 minutes after the end of my shift to send someone to the cash window to replace me. If I clocked in 10 minutes late they would get mad at me, so why should I have to wait 10 minutes after my scheduled clock out time to leave?