The purpose of a DUI administrative hearing is to determine if a license suspension is lawful. Some defenses that may be used include:
The driver was not drunk driving – There is insufficient evidence that the driver was over the legal limit or under the influence of alcohol or drugs at the alleged time. Proof may be shown by test results, witness testimony about the individual's actions and demeanor, and driving behavior.
Probable cause – A law enforcement officer must have probable cause to make a traffic stop. A violation of the driver's constitutional rights may prevent the officer from imposing a license suspension.
A refusal did not occur – The officer is incorrect in their allegation that the driver refused to take a chemical test. Either the chemical test was not offered, or the defendant agreed to take it and was not allowed.
No warnings – For a license suspension to be valid, the officer must inform the driver of the suspension if they refuse. If the officer forgets or fails to give warnings, it is invalid.
Right to request a hearing – Along with informing the driver of implied consent laws and the need to take a test, the officer must also notify the driver of their right to request a hearing. Missing this requirement can result in the suspension being thrown out.