I will begin by saying that I agree in principle with the UFC/Boxing situation you describe, however fighters are always instructed to protect themselves at all times, so they built that possibility into the sport. I even abhor the idea of the color changes to the ball sets. Now that is out of the way...
I have called fouls on myself many times and in a couple of cases my opponent argued that I was wrong and did not foul but I know I did, and I gave up BIH.
Having said that, however, Shane and Joey's situation is not the same thing. Preventing your opponent from fouling (hasn't happened) and calling one on yourself (happened) are different. Also, it's mostly a discussion because of Joey's age. If it was Mika or Sky who made the mistake (yes, I know unlikely maybe even ridiculous but that seems to be the realm we are in now) then we probably are not discussing this at all.
Now, let's tweak this a bit and put it in this scenario: Shane sees that Joey is about to shoot the wrong ball and he stands up and yells "Wait! Don't shoot", in the meantime Joey has realized his mistake and is changing on his own. Shane has now committed a foul by addressing his opponent while he is at the table. He might even face the possibility of loss of game as unsportsmanlike conduct (again unlikely but not impossible - see how fun this can be!) for talking to his opponent. Joey cannot say oh I already knew I was shooting the wrong ball. It doesn't matter now, according to the rules Shane has committed a foul. What happens now in this situation? Oh, wait you don't care what the rules are (I didn't want you to think I forgot!) You could say that since Joey acknowledged it Shane is fine, but you can't because you won't let Joey own it in the other scenario so why should you listen to him in this case, especially over an official... (I know it's crazy isn't it! but now we have scenarios with ceasefires and snipers shooting peacekeepers)
Another scenario Joey is shooting a shot where a scratch is in play. Shane sees that the way he is striking the cue ball he is nearly certain to scratch. Should Shane step up and stop him in that scenario and tell him how to hit it to prevent the scratch? (These fantasy scenarios just never stop do they...)
Shane did nothing wrong.
You say "I don't care what the tournament rules are..." (that’s twice I didn’t forget) Then you should not be playing in that tournament. By making that statement you are saying a player should be allowed to set rules outside of the tournament for their matches as said player sees fit. What if they don't like yellow shirts because they find them distracting. Should they be allowed to force their opponent to change it? Forget ball color, forget betting. Playing pool is Shane's job. It's not our job, it's our hobby, it's something we like to do and watch. It's Not The Same Thing for him as it is for us. You cannot micromanage every aspect of every situation from every player’s perspective. It's another fantasy, another never ending story and it's a story that no one wants to read and shouldn't have to be written... (Much like this post - I apologize to everyone else... I seem to have suffered nonsense overload...)