Pretty typical for St Louis. I've had city bus drivers leave the bus to run into a convenience store for a drink while sitting at a minor bus stop.
I don't see anything wrong with this. It's pretty typical for Houston... I've experienced it many times. A lot of agencies don't schedule adequate time for drivers to get breaks, and most bus routes have a lot of recovery time built into the schedule. If it can be done without getting more than 5-6 minutes behind schedule (since you're an idiot if you're planning out a route based on the assumption of EXACT SCHEDULE ADHERENCE from a bus), I say let 'em have their snacks.