We have a colleague at work, lets just say a gentleman of advancing years, he is quite opinionated on a lot of things so gets quite a lot of stick - which he takes in good heart, and the day rolls on.
He is however very good at spotting things that if left unattended will cause an issue. I like to have him around when we are doing a PDI on a car because if a wiring connection looks less than optimal, or maybe will rub on a corner he will spot it. His experience with building and maintaining rally cars has opened my eyes to the pitfalls of routing wires and pipes etc, and the need to examine connections that we otherwise would take for granted to be good.