I think the cashier isn’t the one who’s going to catch flack for making the owner more money than he was supposed to. You bet your ass he’d be looking for a new job if the pump was undercharging customers and he didn’t take it out of service.
The cashier’s incentive is, presumably, just to keep his minimum-wage job. If this is an at-will state – which Texas is – how do you think the conversation would go?
“Hey, minion, why is that pump out of service?”
“Well sir, it was overcharging customers, so I turned it off.”
“I don’t give a crap about that, I’m down 12% in throughput. Turn that blasted thing on, now! And the next time you pull that sort of stunt without clearing it with me, you aren’t coming back.”