Good points and a good video--thanks bwf. IANAL but I believe the difference in size between Mr. Ha and his assailant did give him legal ground to use a weapon. Likewise, skill could be a similar factor: if you're a 1st dan black belt being attacked by someone like Bruce Lee, fists and feet won't get the job done.I've been meaning to watch that for a while now. Good video series, and brings up some good points.
Lesson one= Be the first party to contact the authorities once you've been in a violent self defense altercation. Articulate what happened, that your actions were justifiable / reasonable, and everything you did was to preserve your life. It appears in this particular situation, he defended himself with the knife and then went home. The injured attacker spoke to the authorities first, therefore altering the narrative and putting the crosshairs on Jarred. After taking the attackers statement (who claimed to be a victim) they had to find Mr Ha, go to his home to get him, thus making him look guilty.
The other is to not live in Seattle, haha. The proudly displayed 15' tall statue of Vladmir Stalin in Freemont should serve as a reminder that the general public might not have your back if you are faced with a violent altercation and have to meet it with more violence. This one hits close to home, being that I am a resident in the Peoples Republic of Bloomington.
Lastly (and a large part of this is purely speculative), learn how to fight with your hands. It's a perishable skill, and must constantly be honed. No matter how good you are, someone is better. Even if you are the best, someone is stronger and younger, and can still kick your ass. Admittedly, I have no idea what his skill level is; He might be a 10th Dan black belt and due to his attacker being so much larger, he was simply overpowered. But my point being, it was a one on one empty hand encounter. (In the eyes of the authorites initially) one party chose to deploy a knife and took the fight to the next level. In his defense, the attacker escalated the attack by driving his head into a car and Mr Ha's response was considered justified. Let me be clear, I am in no position to speak on the technicalities of law. But from my understanding, most states have a expectation of you being able to (reasonably) defend yourself with your hands if you are facing 1 unarmed attacker. If you have an injury or handicap (elderly, much smaller than your attacker, etc....), obviously there are many exceptions. 2 + attackers or an attacker with a force multiplier (such as a weapon), different story