Found this today, thought it might be a nice addition to this thread.
As I understand it this flexible gas tubing should not be installed through an exterior wall unless it is sleved with a larger diameter rigid pipe, and the exterior portion should also be protected from physical damage due to being less than 6’ above grade. In this case it is an improper instalation and seems a poor choice overall. Preferably this should be rigid pipe through the wall and flexible connector just for the gas log fireplace appliance.
I am curious to know how my fellow inspectors would write this up.