Another huge one, although I guess it's more of a blunder than a plot hole, is how after Sue Ellen shot JR three times in his own home, after her accomplice had broken the door in, they could have allowed Sue Ellen to get away with it. Where is the drama without consequences? It was the worst resolution to a Dallas cliffhanger ever.
A man's home is broken into by two intruders. He tells them to leave but they refuse. Then JR picks up a gun and tells them to leave, but Pearce, being the genius he was, decided to rush straight towards the guy with the gun to fight him. Wow! The word stupid doesn't do that justice. Bringing a knife to a gunfight is stupid. Running straight at a guy with a gun pointed at you, when you could just leave as he asked, is just a special kind of stupid. No wonder he ended up dead. Human survival requires at least a somewhat reasonably functioning human brain. Man is the only animal that cannot live on instinct. Reason is man's means of survival.
Ultimately, what the police had was a case where a man and a woman broke and entered into a man's home, refused to leave, assaulted him, and then when the resident of the home vanquished one of the intruders, the other intruder attempted to murder the resident of the home out of spite, since the resident of the home just won a fight with her shack-up.
So Sue Ellen pleads self-defense and they consider it????
If two people broke into your home, threatened you, and physically assaulted you, necessitating that you fight one of them to the death to save your own life and then the other one shot you, how would you feel if she claimed self-defense and the police actually considered it? Self-defense in your home she had just broken into? What are you guilty of, making their break-in and assault too dangerous? That's almost as bad as someone stabbing you and then suing you for dulling the blade of their knife. Oh, here's the best part- if it was "self-defense" how does she explain shooting you three times when all you asked was that she leave?