When Laura punches Nellie, she does so hitting her on the left side of her face. When Laura goes to apologize Nellie's right eye is black and blue.
Three candidates are named for the final cow judging but at the finals, four candidates are shown.
After punching Nellie, Laura is sent home from school, despite the fact that the altercation didn't happen during class time or on school grounds.
Albert says Fagin's sire was a purebred Hereford (a red and white breed). Fagin is actually a purebred Angus (a solid black breed). While Herefords and Angus are crossed the resulting calves normally are black (instead of red) with white markings.
Doc Baker says husk comes from pasture grass. Fagin the bull never sets foot in a pasture. Only the barn and the corral.
You can tell throughout the episode a different calf is used. At one point the calf is taller than Albert then in the next scene Albert is shorter than the calf.
The bull Fagin is seen with a modern cattle tag on his ear in the first view of him grown up.
Cattle ear tags started in Canada in 1913 and were not used in America until 1945.
Pa Ingalls would have had both the older kids raise that bull together. And when he went to the fair he was only half grown.