You can literally get your MOT, get stopped right outside, be given a rectificatin notice, ride back into the testing station, get approved, ride to the police station and present your succesful rectification notice, then get stopped again outside the police station... Not that it's ever happened, I think, but it could. The system works
Still, it's only the daft ambiguity that means I can get my bike easily through an MOT, so I chouldn't complain.