Depends on the construction company. On a lot of jobs today, violating safety rules will get you thrown off the site immediately.
I just had to do that. Framer's were working off stacked drywall buckets on top of a Baker scaffold. I told them no, they called their boss, who called me and asked what the big deal was. I told him if I had to explain it to him I would find another framer.
We had our roof redone after hail damage. I was home and heard all the compressors go silent and no movement in the roof. I went outside to see why and there was an OSHA rep talking with the supervisor. No harnesses and no tie off ropes.
Before they started that morning I was joking with the supervisor that no way would I be on that roof as steep as it was.
I never asked the cost of the fine but I am sure it was substantial.