Yeah. They should move that old wooden stepladder in case the guy falls, so he doesn't land on it.
Actually it's fine... I would walk that plank. Though the prop ladder would be tied to the extension ladder, and so would the plank. So long as his buddy don't decide to go get a beer, it can't really leave.
But then, normally I would be the one standing on the bottom of the extension. I make a marvelous counterweight.