I'm not sure the dog is enjoying this. There again she's with her master, doing what he's doing, going where he's going. Perhaps she's thinking this is as good as it gets. Maybe it's only watching humans who are petrified and think it's wrong. Zero chance Bob or Sophie will be doing this.
I see on todays BBC news that the young man in the video undertook one daredevil stunt too many. RIP.
https://vimeo.com/95917728 ( Sorry. It won't link. You'll need to cut and paste )