I read one of the AGoners say he "snuck around and swapped this or swapped that to PROVE" how people were so gullible. THAT NEVER happened, EVER. NO one would let anyone near their gear for that.. NO ONE, pure and simple a BIG FAT LIE. BTW that guy quit posting, too.
No, but in my limited experience, he did post a video with recordings where he claimed a clear "audible" difference with HFTs and without.
Guess where he placed one of the HFTs? Right next to the microphone. Not a foot away, I mean right next to it. Perhaps that was ignorance, but obviously that is going to impact what the microphone records. Someone analyzed it and showed a clear level difference from it.
Been to a demo once, and definite coaching on hearing changes, but I won't fault him, as that is common at audio shows, and county fair product sales.