Well, Sandan. I don't know what your background is, law enforcement? Attorney? Or? I also don't know much about how the system works in the UK .
As for the part where they are subjective. I guess you can say they are. But for me, unless something the officer says or does to the contrary, I would believe the officer everytime over the civilian person. I would assume most modern day officers are trained, at least to some degree, in looking for DUI's and recognizing and giving a person the fst's. If you ask Shane, I think he would probably say there are a few more reasons to giving the fst's? Such as driving behavior, speaking, look and smell. Of course I could be wrong.
I don't understand how a handheld breath test would be considered an "intimidation plot"? Especially if it shows that he has little or no alcohol in his system.
My .02 only.