I have no problem with the lowered limit. People shouldn't drink and drive. However, I really don't believe that the roadside sobriety testing alone should be sufficient for charging a DUI. First of all, the testing is subjective. Secondly, not all police departments these days have cameras, and police have been known to make facts fit their narrative. I will give an example which happened to me. I am a physician and got called into the hospital at 1 am on a Saturday night. On the way back from the hospital I got a flat tire. Changed the tire and drove on. Unfortunately the spare slowly went flat about a mile from my house. Being that it was 2:30 am, I was tired and just wanted to get home, I decided to drive up the shoulder of the 2 lane road the last mile. At this point I was "pulled over". The deputy was sure he had a DUI stop, and didn't believe my explanation. He asked for me to do a sobriety check and I complied so that I could just go home to bed. Now, walking a straight line is no big deal most of the time. However, do it on a dark night, in front of a police cars bright headlights, bright spot light, and painfully bright flashing lights, when you are extremely tired, and it is a different story. I wasn't falling over, but the strobe effect from the lights was disorienting and I had to step off the line a few times. Then I was given the nystagmus test and apparently had mild nystagmus, which can be caused by sleep deprivation as well as caffeine. Based on these tests he felt he had sufficient probable cause and asked for breathalyzer which was 0.0%. Then he started asking about drugs and said he was going to arrest me and take me in for a blood test. Before he did that apparently he called in a more experienced officer and another squad car rolled up. I went through my story again and eventually they let me go home. However, it could have been much different, and even an unfounded arrest for suspicion of DUI is a big deal, and would have caused me huge problems with my job, my medical license, and my hospital privileges, not to mention my reputation. In any event, unless you have corroborated (video taped) evidence of severe impairment, the basic roadside testing they do is insufficient to stand alone in my opinion.
I'm not sure how this fits with the DUI limit. For one thing, as you say, you WERE driving in what any police officer would call "suspicious driving behaviour", I would expect a cop to pull one over driving along on the shoulder.
But I agree, and there are several videos of Field Sobriety Tests where many, many people would have a problem doing them stone cold sober, in their living room, after being given warm up time. Add to the the flashing lights, also the noises if you are on the side of a highway of the cars rushing past, night time with bad lighting...yeah. I''m pretty sure from what I've seen of FST that at least a lot of the variation are "rigged" basically. On the other hand, a half-smart habitual drunkard with determination could practice standing on one leg, eyes closed, etc. and maybe pass even with some alcohol in their system. Also what about people with inner ear problems, etc. ?? It's rigged. I think they REALLY actually are checking your responses, manner, etc. A person under the influence do all kinds of "prep" and try to stand TOO straight, etc.
But that aside, you say you don't think they should charge one with DUI for failing FST, but later mention he wanted to take you down for a blood test. So, though inconvenient, that ought to have been enough if you were blood tested so they didn't charge you if it had gone that far.
It just will happen though, at 2:30 a.m. driving on the shoulder (flat tire or not) one is going to get "checked". After that you can only hope the cop is not out for getting to write DUI at any cost, and has some sense, and is objective.
I used to drive cab (in a suburb of Chicago, then in the Bay Area in California) and both places I could just about set my watch by watching other traffic. Bars closed at 2:00 a.m. and by 02:30...it's was like crazy time. Remember driving over the Bay Bridge, and I swear just about EVERY other car on the bridge was weaving, speeding up, slowing down, etc.
Sorry you got unlucky, but the copes prejudice (assesment of the situation before he even started interviewing you) made him predisposed to already have judged you DUI or on drugs. Once someone does that it gets to be an ego thing, they don't want to change their mind and be "wrong"...so they dig for more whether it is there or not.
Roadside tests are not much valid.