Comments

Either the customer was being a total jerk and those on line heard and decided to take action into their hands, the one slapping the cheese on the filet was new on line and assumed "on the side" was literally on the side of the filet, OR it was just an honest mistake from having to assmble so many burgers at a time and the cook just closed the box before putting the cheese in, which is most likely what happened. It happens and I know because I've done similar mistakes before. It's just an error in the autopilot mode you're in, not because we're lacking, incapable or stupid.