This is a thought that has been running through my brain, I cannot see any other way that a bolt and nut would be in there. The tech is a very dedicated and stand up young man, I cannot see him doing it on purpose or being that inept in making repairs. He is the only tech that is allowed to work on XLR's and there three other XLR's that he works on regularly. I know all the owners and they have never had any issues with his work or work ethic.