Substitute "child" for "dog" in what you wrote above and see if it still makes sense and seems reasonable.

I've seen the sweetest, most well behaved, most friendly dogs, in just this situation, and it's not pretty. It's very stressful to the dog to watch its owner disappear high up on a cliff face, and then wait for hours in a strange place, not knowing if the owner is going to fall off the cliff or come back safe.

A good dog in such a position will still behave well, but they will be very sad and increasingly anxious all day long.