The problem is that some cops have little better to do than pick on people. If this officer wanted to be a dick, even if his friend wanted and could have gotten a breathalizer test right there, a cop could sit him down and watch him for 20 minutes. Results from breathalizers cannot be admitted as evidence if there's a possibility that a foreign object was in the mouth (Food, drink, etc... putting a nickel in your mouth will "numb" the breathalizer, for example) less than 20 minutes prior. The officer then could have used that time to entertain himself by searching his car, etc...