The GM "oil warning" is based on mileage since last reset, not oil level, and it's based on a configurable mileage interval if I remember right. There's a separate sensor/warning for low oil level and it will tell you to immediately shut down the car. As long as that is not the warning you're seeing, as AutoSlash noted you will be fine to drive the vehicle around.
Does MIA have the high-resolution damage cameras at the exit? You can't miss them, it's an array of white cameras and lights while you're heading out. Many (maybe most?) stations now have these, eliminating the need for a human check at exit.