Not only did they use a cheap RCA cable, they also used a cheap source and amp.
No one could tell the difference. The cable being the least of this.
It confirms what I've long found to be the case. Cables don't matter at all. Digital sources are all about the same. Amplification matters as much as it is adequate, and what's most important is having a good recording and good speakers/headphones.
I do think you can get different sounds from amps. Tubes introduce some character (often pleasing, and that can be backed with measurements) but aren't necessary for great sound.
I like to see people get great sound and enjoy their music at the lowest possible cost. Thankfully, that can be done for very reasonable prices today. Then there are those who want status symbols. That's OK. Some of the expensive stuff is beautiful and works well. Enjoy it if you can afford it. What I really want to see is high-end audio become more mainstream and popular. Everyone should have great headphones and/or speakers without worrying abou the stuff that doesn't matter.