If he can go book the MOt with a garage, pref a guy he knows working their and say he booked it before the affense, he will get away with it.
tho........... not sure it will work unless he mentioned it at the time the producer was made out.
this is secound hand information but i was assured it was true.
i.e. MOT runs out, you get pulled over day after, sorry officer i dont actually have a vaild MOT certificate as the vechile could not be booked in untill 2morrow, officer makes a note on producer, your produce your leience and then the new MOT couple days later.