The boss is temporarily working in US office from the headquarter in Korea. He doesn't take it seriously about DUI.
If your husband gets pulled over and charged with a drunk driving offense, his boss will not have any criminal responsibility and the fact that his boss encouraged the drinking and driving will not be a defense. Ultimately, it is your husband’s choice to drink and drive. If he wants to drink with his boss, he should limit his alcohol intake or make other transportation arrangements. Judges are harder on DUIs now than in the past because of the accessibility of Uber and Lyft.