He may have not mentioned EVERYTHING regarding the RC challenge, but for the most part, he is correct. With enough equalization one would be hard pressed to tell the difference between a mass produced budget amplifier and a hand built high end amplifier. Granted, some amplifiers have higher noise floors than others and that may could contribute to a noticeable difference along with the fact that some amplifiers purposefully color the sound. In the end, if one can get them to measure the same they will sound the same!
Then again, you may have ears of gold and could be that person to take $10,000 from Richard Clark! Just think of all the bragging rights you would have plus the fact that you would be famous all over the world.