Well, depending what drinks they had, thats about 8 drinks each over 3 hours, which is around 3 per hour. To be honest, if you AREN’T driving afterward, that’s a decent night out and not TOO bad. I’ve had way more at a party and still had room for more (mind you I knew my limit and stopped). So in that case, overserving? IMO, no. The liquor board could look at that differently but every body is different. They may have been just your typical drunks that night but noone knew they were driving.
It was up to them to designate a driver to drive them home or take a cab.
EDIT: I’m assuming that they were beers.
EDIT: Also, it’s the driving portion that killed them, not the overserving. You are over the limit after only like 2 beers within an hour iirc. So… That’s a sort of moot point seeing as they shouldn’t have been driving regardless the amount they had…