haughtney1
Again, you are making the mistake of confusing 'sobriaty' and having aBAC above a prescribed limit.
The prescribed limit in this act, is very low, and it would be very very unusal to be anything but sobar with a BAC at that level.
You ask for justification for giving the test and of course I can't give you the answer, I was not the officer who made the requirement for it.
Beyond that, and without anything that has been said that shows the administering the test was not justified, the test itself was positive, and therefore arrest was fully justified.
The issue of 'common sense'. Please explain how what you say is common sense could have been applied at that point?
As regards to discretion, there is very little with any breath test, so once a test is administered, if it is positive then arrest is inevitable.
You can try to get the Met Police to give you the justification for their action, but I doubt you will get much of an answer, beyond 'Police were called and breath tested. The test was positive and he was arrested'. The reasons you wont get much more of an answer is because the second test was negative, the matter is now closed, and therefore is is no longer the buisness of anyone else.