No idea. There seem to be quite a few areas where ours is stricter, and only 1 or two where it's more leniant. Although it has always been different. Maybe it's because ours are all government run centres. At least one aspect is unique to our shores though, that's the requirement for speedo to have the ability to display both mph and kph. That came into force shortly after Southern Ireland went metric with kph instead of mph.

Our manual ( not including the updates I think )

http://www.dvlni.gov.uk/Freedom%20of...%20Manual.html

The system you have on the mainland is easier and definitely more flexible. Although sometimes having a system that is pretty much impartial to a pass/fail is better. Other than a retest fee ( £20 or so ) the testers have nothing to gain or lose from passing or failing a car.

My brother moved to London a few years ago. The first car he had to MOT there was a joke. The garage that prepared the car for MOT was the same garage testing it. And it failed !!! Like WTF ?? How can the same place that is preparing a car for MOT, then subsequently fail it.