As a Kansas DUI lawyer, I spend hours every week reviewing police videos and reports on my clients. One of the things I am evaluating, is whether there was probable cause to arrest my client. Alas, if there isn't probable cause for the arrest, I can often suppress the subsequent Breathalyzer results or refusal. I have taken many classes on administering the field sobriety tests and therefore carefully scrutinize whether the police officer correctly administered the tests. This is because, if the standardized tests aren't administered correctly, then the results are compromised. In fact, the NHTSA manual even says exactly that.
Unfortunately, the Tennessee Supreme Court ruled last week that law enforcement may arrest a drunk driving suspect, despite passing the field sobriety tests! They decided that the evidence of the field sobriety tests can simply be used for trial purposes. This decision is highly concerning to people who value liberty.
However, the judges made their ruling based on the totality of circumstances, stating that sobriety tests alone are insufficient negate probable cause, when there are other clues of impairment, such as odor of alcohol, poor driving, admissions, and etc.