Plot hole: In the first season, Lucy Ewing had an affair with Ray, the farm hand at South Fork. Several years later, it was revealed that Ray was actually Jock Ewing's illegitimate son, making him Lucy's uncle. However, the subject of their affair was never raised, even though they surely would have been at least somewhat traumatized upon learning of the accidental incest.

Revealing: At the start of every episode, during the credits, you can see the shadow of the helicopter filming the aerial scenes.

Plot hole: The entire ninth season of "Dallas" was subsequently revealed to be a dream that Pam Ewing had. This opens up a vast can of worms. One glaring problem was that Katherine Wentworth had been actively scheming against Pam and Bobby throughout the eighth season; it was she who supposedly killed Bobby at the end of that season, hitting him with her car (though aiming for Pam) in a crash that killed her as well. But that happened in the dream. When Pam woke up, it was supposed to be the next morning, immediately following the events in the last episode of the eighth season before she went to sleep. Why, then, is Katherine Wentworth no longer anywhere to be found?