The last failure I had a few years back was a ball joint. I said to the guy I think the tie-rod is had it because the boot has a crack in it and was ordered to come from Japan. He checked everything but said no the tie-rod was fine and failed it on a ball joint.
A few days later my tie-rod replacement showed up then I got a new wheel alignment. I took it back to VTNZ and they passed it.
So I call them testing personale or officers not mechanics.