Here's my shot at a simple perscription for an amazing situation. I cannot believe it happened, but here is what I would do to handle the riot...
Hong is clearly disqualified. Hong exhibited extreme behavior in their deliberate attempt to harm Chung and to ignore the rules completely. By Article 14.5.2.f, Hong is immediately disqualified.
Chung is the rightful winner of the match, but will need to find a new coach. The headbutt occurred after the match (if it occurred after the declaration of the Gam Jeom). Chung's coach should be suspended from all coaching duties for at least one year and possibly brought up on charges from Hong for the headbutt. Some could argue that the coach was only retaliating on behalf of their fallen player, but it is clearly unacceptable and unethical behavior for the coach.
Those are my first thoughts, any others?