Just because you receive a call does not mean it is safe, and it puts you under no obligation to put the lives of your staff as well as your equipment at risk of harm. I personally have walked away from a Texas Department of Public Safety trooper more than once when they refused to give me a lane to work a scene. My life is worth more than your set of tires and is worth more than any vehicle on the road. You should have policies and procedures in place, and trust the judgment of your staff to make the call in the field. If something is not in a calculated, safe, controlled environment, refuse the call until it is controlled in better favor of your survival. This scene was a failure in judgment, policy, and procedure.