Dave Henderson was arrested for drunk driving on Friday. The police said that he was stopped for going 68 in a 55-MPH zone and for failing to signal a lane change. They didn't indicate what led them to believe that he was drunk nor would they confirm that he took a breath test.
Unless people drive vastly different in Washington, those things would not be enough to pull someone over. If it happened in the South, I would wonder about racial profiling.