To me carrying dog off course is unacceptable. I can however imagine couple of situations when I would do that, too.
Most of the time, though, people are just frustrated and disappointed that dog didn't do what they wanted and they always blame the dog instead of realizing that perhaps their handling wasn't the best. I've never carried my dog away, but I've had moments when I was disappointed and bitter, blaming the dog.... Funny thing is that later on I either thought about the situation and realized I did something wrong or watched the video that cleared everything up and of course, it was ME who was to blame. I think dog doesn't deserve that kind of treatment. They're doing their best and we can either blame bad handling or bad training. Dog is doing his best under given circumstances. Luckily it doesn't happen over here often. People usually try and finish their runs. Only one lady on Saturday interrupted her run, put the dog into heel position and left the ring. It was her fault they made an error, but well..... at least she didn't beat him. On the other side, there are many things that bother me when watching other people. Another thing that I really hate is when handler and dog finish their run and handlers don't even bother to pat the dog or anything. They ignore him completely and there's no reward for the dog.
I've read this yday on Facebook and it's something we all should remember when running
"It is one thing to desire to win to prove you are better than others and prove to yourself that you are worth something. It is another thing entirely to rid yourself of ego and to love the process and moment so much that winning is a by-product of passion.
When I see the smile on a dog's face as he runs agility, I know he's already there running with passion, unconcerned about outcome. We are the ones that need to learn the lesson."
It's really sad when you see how sometimes people really only care about winning and they are awful to their dogs if it doesn't work out....
As for Lisa&Hoss video..... It isn't what it looks like. Everyone saw her video from last year's WC where Hoss knocked down a bar and she was so professional and positive, finishing her run, having a blast with her dog. She also always rewards the dog - it's the first thing she does when she finishes her runs. I actually know the whole story behind this video, because it was in Kladno, CR and people discussed it in czech agility forum page. People who know Lisa and were there with her said that Hoss made a mistake for the first time, so she wanted him to "do it right" and took him back on DW, but then he was all confused and didn't react on his release cue, so Lisa took him away. Some of her closer friends said that Hoss is "momma's boy" and he hates making mistakes, so that's what basically happened and why she took him away.