I was always told that you eliminate roughly one drink per hour from your system. So it is possible that they did that feat over a longer time span. Staying up

I was always told that you eliminate roughly one drink per hour from your system. So it is possible that they did that feat over a longer time span. Staying up all night drinking then hopping in the car seems much more reasonable (at least for how to achieve that BAC, and not as a decision you should make in life).