A BA level like this means that he likely had about 6 beers (or shots of hard alcohol) still in his system. An average person “burns off” about 1 drink each hour. So if he drank 4 hours earlier, he had WAY more than 2 beers. By the way, I heard “I only had 2 beers” so many times in my career that “2 beers” became a cliche.