If May where to fire a weapon straight up in the air in an underground bunker like this the ricochet would be very loud and possibly deadly.
When flying out of the Earth's atmosphere the team uses the term MECO which stands for Main Engine Cut Off. They use this term while talking about the thrusters. The correct term, if any, would be TCO. Also, they did not call out or throttle down the engines when they approached "Max-Q." which is the maximum dynamic pressure exerted on the spacecraft while leaving orbit.