This is pretty hyperbolic. Not noticing poor results does give some idea of the quality of the work done. Of course it's not a perfect system, of course more re

This is pretty hyperbolic. Not noticing poor results does give some idea of the quality of the work done. Of course it's not a perfect system, of course more references would be better, of course the work being judged by a known expert would be better. If I know someone who I think is sensible, and they hired someone to do some work on something that they know nothing about, and the thing was fixed and has kept working for a good amount of time, that is useful information. What is your proposed solution to deal with this perceived problem? Hire another expert to judge the work (how do you know to trust that expert)? Be an expert in everything yourself?