These two are not junior engineers. And I doubt that only two people knew about it. If Volkswagen developed diesel engines for the US market and problems arise

These two are not junior engineers. And I doubt that only two people knew about it. If Volkswagen developed diesel engines for the US market and problems arise to meet the requirements these problems have certainly not been solved in a dark back room, over a beer by two engineers. This must have been a topic on a high level. And also the solution must have been discussed.