I watched all the video parts to that seminar. Very interesting and educational. That whole fin punching thing is mainly for spawning. I personally would not do that to fish in my community. Maybe if I was spawning fish. I kind of feel bad doing that.
On another note , when it comes to the cichlid hobby , I think Don is the master of knowledge of cichlids and probably the most respected person in the hobby.
After recently contacting him myself , I personally did not care for his people skills very much.