Since EngCo had no knowledge that BuildCo have such unique rules, it could assume that all internal proceedings inside BuildCo have been carried out properly. In reality that is not true and there is indeed an irregularity going on inside BuildCo, since Jenny told Matt to take care of all issues but did not tell him that those issues do not include important contract. However, it does not affect EngCo. EngCo has no actual knowledge of the irregularity that is happening inside BuildCo, and was therefore not affected by internal management irregularity. EngCo can also protect itself by using indoor management