After awarding a contractor a due diligence mapping for more than125 sites, a tower owner hired another firm to check the accuracy of one of the contractor's first reports. It was missing multiple antennas and lines and shortened the tower's height by 20 feet. The contract was pulled and the reviewing contractor was awarded the project. A tower site manager was on location, but was unobserved by the contractor who pulled up in his pickup truck to map the self supporting structure. The tower technician proceeded to open a lawn chair in the bed of the truck and in a reclined position, used binoculars and a camera with a telephoto lens to map the tower, the last one he did for his company.