But how can you verify that the two independent companies aren&#x27;t both using the same faulty code? You could ask someone under oath, but how would <i>they</i> know whether an employee bought or stole code from the competitor, or they both made similar errors in implementing a published algorithm, etc? As mentioned regarding Volkswagen, black box testing doesn&#x27;t necessarily cut it (especially if the flaws are statistical in nature or triggered in unusual circumstances, and more so if they are deliberate).