This is a tough one all around. It was a combination of factors that led to this uncomfortable outcome. All of them have been discussed here already. The kid was put on the spot when he realized what had happened and he so wanted the win that he may well have lost sight of the bigger picture here.
I've seen in a major tennis match when there is a bad call the opponent concede the next point. That shows class to me. For me the jury is still out on the behavior of a 16 year boy. I think it is up to us as adults (particularly those who are close to him) to guide him in ethical behavior. I suspect he is a good kid, very new to the tournament scene and to put pressure on him in a situation like this is a little unfair. What kid wouldn't want a win?
I also feel that TD Dave Hemmah did the best he could with a bad situation. Sometimes there are gray areas where a TD must act in the best interest of the game and I believe Dave did here. Greg is by far the more experienced of the two players and for that I put the most responsibility for this mistake squarely on his shoulders. If I "snooze" a foul by my opponent in a One Pocket match and forget to spot a ball, I damn sure can't bring it up after he has eight balls. Greg snoozed a game and protesting after the match is a case of "too little, too late" imo.
I give the kid a pass on this one and would probably do the same for an adult. The time to make a correction on the match score was much earlier in the match, not at 6-6. If the scoring error had happened a game or two before, then everything is entirely different. This type of mistake has happened before in tournaments that I've worked, and if it is caught quickly we correct it. But if the match ends or is hill-hill that is too late.
Either way, tough call and no "winner" here whatever the result. As for me I'm glad to see young kids getting into pool tourneys and I was happy to see several of them at the Swanee. I will do my best to support and encourage them in our sport, without putting any undue pressure on them. One of his mentors in Ventura is Jerry Matchin, a friend of mine for decades. He told me that this young man is a good kid and that's good enough for me.