A friend of mine shared that on FB today. It would blow my mind to walk by and see him jamming out on the street.
I saw him just sitting at a restaurant one time, and it made my week. This would be next level.
If the story checks out that he was just handed the guitar to play a few licks, I'd bet he heard it and asked to give it a go.
That setup sounded really nice, even in open air.
I first met Billy at a wedding back in my high school days, and then again when he would stop by the drop zone in League City (he was on a blue Suzuki GSX 1100).
He never had to try to be cool. He is cool by nature.