(I listened to that performance online at the PHC archive, and it was indeed tremendous. So much so, that host Garrison Keillor quipped afterwards that it was probably discouraging to novice guitarists. Emmanuel replied that he hoped it was encouraging...)
You can be the judge. I tracked down a video of the same number from one of his concerts. (This is not from A Prairie Home Companion.) It's a medley of the song "Windy and Warm" and "Classical Gas," written and initially performed by Mason Williams.