I don't think their employer held an expectation they'd be back at work at 1AM Saturday morning after their 7 hours drinking, irrespective of the liability situation. Perhaps a more orthodox course of action would be to work an additional hour (if there was something to do) then go drinking. Rather than stop work, go drinking for 7 hours, then come back to work. It doesn't "Pass the pub test," if you'll pardon the pun.
