Yes, it is really nicely done!
We do a lot of qinna ourselfs at my school, and although it is hard to get a good grip if someone comes fast and furious at you, or if he is wet and slippery, it is a definite "end fight" skill if you get hold of your opponent. Regarding his will to "cooperate" with the pain chinna inflicts, you can either put him down and secure him, like in the video, or simply break and rip his joints and limbs, thus reducing his ability to get back at you, greatly.
Especially people under the influence of drugs and alcohol have a greatly reduced sense of pain, and tend to simply rip their joint to get to you. The hurt will come later, not right away, so be carefull with them. Against those people, unballancing and disorientating techniques work best - a clean knockout put aside.
Best,
Sascha