That shows how ridiculous and dyed-in-the-wool driving instruction dogma is in the UK. Many drivers have misinterpreted the IAM advice over this, which is if you can demonstrate competence, fine, but if you can’t retrain your left foot, don’t do it out on the open road. I have never ever heard of anyone failing their test for left-foot braking an automatic, but one ex-driving instructor, who insisted on driving right foot only, managed to kill himself trying to right-foot brake his Mini automatic in a supermarket car park, when left foot braking would have retained full control of the car.