I had an operator do this with their 10 plus years experience. They were fired on the spot.
Another threw a 8Lb. Disk through the top of the Lathe that also went through the roof of the shop landing one parking lot over. Luckily there wasn't a car in that spot that day.
Scary when someone that is supposed to be experienced can't cut jaws or know what amount of chuck pressure they should be using.
This taught me to check everything after the operator touches a machine no matter what experience they say they have. They might be insulted, but that's tough cookies. Takes more time but at least nothing gets wrecked.
A down machine means no money and I really do not like explaining to the boss that they hired an idiot.
Sorry to hear about your misfortune WOLOG.
At least no one got hurt. That is always a plus.