Quite possibly a miss programming the CNC machine caused the machine to crash into the part. Seen parts like that. Often causes more damage to the machine than the part. A major crash will be heard throughout the plant and floors will shake.
We call it a CLeM. (Career Limiting Move) In one plant there is an actual trophy award featuring a piece of a half million dollar botched job mounted on a walnut plaque. Often results in being walked to the exit by security.