It's an awkward position that your employer has put you in. Making you choose between your safety and your paycheck is never acceptable.
Ultimately, your safety and well being rest on your own shoulders and going home instead of risking possible injury or even worse was the right call.
Anyone who says differently is on some juvenile macho trip and will learn better someday. It will be an expensive lesson.
I'm surprised at the lack of safety-mindedness I see in so many contractors.
The shop owner is putting himself in a no win situation if he condones such activities.
Is he actually hoping for a workman's comp. claim?
In my shop, If I catch anyone doing working in an obviously unsafe manner, I fire them on the spot.
The last thing I need is an OSHA violation or a workman's comp. claim not to mention how bad I would feel if one of my guys got badly hurt just to make me a few dollars.
Sounds like you are the only one in your shop that has his priorities straight.