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.

That's like saying "my meal begins from the time I start driving to the restaurant". It's just not true.

It’s more like saying your meal begins when you sit down at the table, which is a proposition that a lot of people would agree with.

Certainly every chef-run fine dining restaurant would agree with that.

It's nothing like that, but you're entitled to be confused and wrong.

Technically it's okay to be confused and wrong, but it is not really okay to be vocal about it. It just steals people's time. Maybe it is deliberate trolling, how should we know? Better to be moderated out

Incorrect. A rest is as important to music as a note.

Found the jazz musician :)