Hah! Thanks for sharing this vid, I walk past this piece at least once every month (or more) and when it was first installed I was "chuffed" to have a genuine Andy Goldsworthy closer to home than the ones in the Presidio or down in San Jose...cause I feel an affinity to him (we share a surname)!
I almost met him at a gallery opening at the Haynes gallery in SF but he had done his talk and left before I arrived, but a friend (who's an artist herself) spent a couple hours talking "ART" with him and said he was wonderful (plus very serious about his art)...

Maybe next time he visits SF I will find out earlier and get a chance to shake his hand.
Then show him my Drivers License