So I am covering for one of our air shuttle drivers while they are on vacation, and on my back to the building my rear view camera decides it no longer wants to work. I write it up and put it under "safety" on the DVIR. As usual the two guys who grab these trucks to setup for preload was about to take it when I mentioned the write up. I was promptly told that the rear view camera not working is not a safety issue and that I needed to tear out the DVIR page I already signed and redo it as non safety. I refused as I always viewed a non working rear vision camera as a safety issue(the rear view camera is safety equipment after all right?). I stood my ground and guy doing setup moved on. I realize you can get by without a working rear view camera, but this was a 24 ft. box truck, and I felt it was necessary. Was I being unreasonable denying them the use of this truck over a rear view camera? Is it right for anyone to tell a driver that they need to redo a DVIR because they think the issue isn't safety related?