I think he is referring to the general standard of restoration for UK trucks vs US. A
lot of people have bought trucks that passed MOT and were advertised as great shape but were not up to the standards one would expect from a truck sold in the USA with the same description.
It is a stereotype and it suffers from the same failings all stereotypes do. It probably gets more play than it should but there is a bit of truth to it.
caveat emptor applies to all trucks but particularly those you are buying sight unseen.