First, a person must assess what constitutes probable cause. Probable cause is the reasonable belief based on articulated facts that a crime has been committed by a particular person. The court will generally consider all the circumstances within the officer’s knowledge at the time of the arrest in determining whether or not probable cause existed.
In a DWI arrest the process of collecting facts for the case begins when the officer sees the vehicle in motion and ends with the decision on whether to arrest or not. In a typical case, the standardized field sobriety tests are significant factors on whether probable cause existed or not. Did the officer perform the tests correctly? Did the officer give proper instructions? These play huge factors in determining probable cause.
If a court determines that no probable cause existed for your arrest then the end result is typically dismissal of your case.