...should you choose to watch this video (Viewer Discretion Advised) you will see that the Brazilian Jiu Jitsu practitioner was the aggressor, he was over-confident of his ability and that got him killed.
The first, and ultimate, lesson of self-defence is to walk away, there's absolutely nothing wrong with that and it can save your life!!
I believe that there is another angle not covered by the narrative of this video and that's the over-confidence and lack of humility that being a successful sports fighter can / will generate...just a thought, but how often do you see it?
Feel free to comment below, I'm interested in people's thoughts...