There doesn't seem to be a conductor at all in this performance, and there certainly wasn't one for the entire 17 months that the rest lasted. (The person in charge of this project, Rainer Neugebauer, is not conducting; the linked article makes mention of a speech before the note was changed, but nothing about marking time.)

Not that I'd expect a conductor to be needed for a soloist performance, but it makes the whole "when the conductor raises his hands" point a little off-topic.