I do believe that the shark is on the line of the first fishing pole, and is raised up out of the water by the pole, and that the dog grabbed it, and slack is let out on the line. But hey, I could be wrong, I still think it is an interesting video, either way. Maybe I’m just a skeptic, the shark not fighting back, and all...
Whoops, at least partially confirmed (on a line), this clip shows just a little further back. Could be alive though.
http://www.youtube.com/watch?v=2jkExrrm_sQ
Thing is, I went to look for another Shark vs Dog and found yours on Youtube.
It looks like the shark had been caught on a deep sea rod and may have been dead tired.
http://www.youtube.com/watch?v=2jkExrrm_sQ
The copy you have was edited by someone else.
Still a cool video.