It's been reported that the assistant director Dave Halls was filling the role of "safety director" in addition to his other duties....and normally you'd have one person acting as "safety director", with no other duties.
And they did this to save money.
I don't know the usual protocol like Hugh and Craig, so maybe they can provide insight....
Halls also had a history.....
https://www.cnn.com/2021/10/24/entertainment/rust-shooting-assistant-director-halls-complaints/index.html