Continuity mistake: When Babe is walking through the house, you will notice that several times his feet switch from muddy to clean as the camera angle changes.
Continuity mistake: The sheep thieves drop their ramp when they leave, but when Hoggett arrives it has disappeared.
Continuity mistake: There is one section where the camera shows the animals looking into the house through a window, but when it shows it from the outside they are looking in through a door. It's around the part where Babe is in the competition.
Continuity mistake: During the sheepdog trial, when all the crowd are cheering after Babe receives full marks, you get a view from the stand. Farmer Hoggett and Babe are standing in front of a pen. Then there is a close-up of Hoggett and Babe, and the pen has disappeared.
Continuity mistake: The alarm goes off at dawn, yet when Babe picks it up it is set for 10:25.
Continuity mistake: Farmer Hoggett is an old fashioned man, and naturally his fences are old fashioned and wooden. However, in the scene where the two sheepdogs are rounding up the sheep, the camera follows one of the dogs for a shot, and you can see the fence in the background is much more modern - it's called New Zealand fencing, I think - where in the shot before it was wood.
Continuity mistake: At the beginning of Babe's competition, Farmer Hoggett removes the leash which then reappears and disappears in subsequent shots.
Continuity mistake: When duchess is thrown outside, in the close-up shot you can see that she almost had the door handle, but the next shot shows that it's higher than her paws.
Continuity mistake: In the scene where farmer Hogget is filling out the application form for the sheepdog trials. There is a postal address line on the form. In the next shot it is gone.
Answer: Rex means that they are both part of the sheepdog family, not that they are closely related. He thinks that when Fly told Babe about sheep-herding, she disgraced her whole species.