How do you know the structure is able to withstand multiple shock impacts? How do you ensure the tension of the supporting guy lines are measured as per Original Equipment Manufacturer (OEM) recommendations?  How do you know that the Blow out Preventer status is checked prior to commencing pulling out of hole? Do you know the weakest point on the hoisting system/structure design and the operating envelope? How do you know that procedures are clear, available, current, and workable? How do you ensure that people are out of the line of fire during such operations?