I get the point that you are trying to make but there is a difference- The State of Hawai'i has already established that you are driving while intoxicated (DWI) if you are in physical control of a vehicle with a blood alcohol content of .08% or higher, regardless of whether your driving ability was actually impaired. The State has also established that if you’re driving or in physical control of a vehicle, you’ve given consent to submit to a chemical test for the purpose of determining the amount of alcohol in your blood. You can refuse but there are consequences. HPD has enforcement authority over DWI laws. They also have enforcement over underage drinking laws but (taking Officer Yoshemori's quotes in context) it's much more difficult to arrest someone for underage drinking because HPD officers would have to establish that a person under the age of 21 is drinking. Hard to do if they're not in the water.