Procedural complacency can transform a routine postflight walkaround into an agonizing, career-stalling medical emergency in a fraction of a second. Following a demanding 3.5-hour instrument training flight in a UH-60V Black Hawk, a flight crew's brief lapse in checklist discipline turned a routine engine shutdown into a severe, preventable injury. This mishap serves as a warning to all Soldiers that a mission is never truly complete until the aircraft is fully shut down, secured and safely parked.