Terrific! Now I have the perfect reason why my playing doesn't always sound so great. My guitar remembers all that time I spent as a really bad beginner and thinks that is the way it's supposed to sound....

I'm actually playing superbly now, but the
guitar is holding us back.... That must be it....
Although the guy's speech did sound a bit like guitar maker's voodoo, I have a friend who I'm sure would agree. He used to play in a classical duo with a fellow musician (both Conservatorium trained) and they both had the same model guitars. They'd been hand built by a very well repected Australian luthier. Both players were very sensitive to the tone and sound of their guitars. But the fun started when they tried swapping instruments. Despite the fact that they were the same make and model, neither guy could apparently get the quality of sounds from each other's guitars that the owner could. It certainly seems to fit with what the guy in the video was suggesting.
Interesting....
Cheers,
Chris