CGB, would you tell me where you teach? I'll ring and have a word.
5kts for luck...You have my permission to kick him in the pods the next time you see him.
Ask him to work out how much extra energy you are carrying by "adding 5kts for luck" compared to the proper speeds. If he doesn't know how to do it, then boot him again, only this time make sure you are wearing steel toe caps.