Our top boss tells a story that has bearing on this one (I'll try to condense). In 1968 Vietnam, he co-piloted his first 'copter in country. The pilot, a seasoned veteran, said "If we take this load, come back and get the 2nd, we'll be last into base camp and the beer will be warm. Let's load up both piles, take it in one trip & be first at the cold beer." My boss had a real bad feeling about it, but figured the pilot knew what he was doing. (The pilot said by the time they get to the Landing Zone (LZ), their fuel used would lighten their load for a safe landing. After several bouncing tries, they finally got off ground, but had to land prematurely and crashed. When my boss learned that he had been suspended w/o pay as well as the pilot, his superior told him, "Yes, you were not senior, but you knew it was the wrong thing to do and didn't act to stop it. Therefore, you are just as responsible for the outcome." My boss said it was a lesson in accountability that he'll never forget.
Hopefully, you will not have to suffer for someone else's disregard for safety, but let's suppose your supervisor or someone else died.... I've worked in plant maintenance in my past life and I know the upper management isn't always supportive of "justified insubordination", but I hope and pray it's different now.