The high failure rate for Red Team tests is known fact, a quick Google search will help. Unfortunately you can't blame this all on the x-ray equipment. My personal favorite was a Red Team member who strapped a small IED to his back with a back brace. When the TSO went to pat him down he showed the guy his brace, told him his back hurt, and asked if he could leave it on. The TSO let him keep it on and the IED got into the sterile area.