Deliberate mistake: When Rafiki comes to the pride rock for Simba's anointing, one minute he is walking through the assembled animals, the next he climbs onto the top of the rock from the front. Physically, even for an ape, it's impossible. It's a deliberate mistake, obviously his arrival would have been much less impressive if he had had to climb the mountain from the side in a slow but realistic way. (00:02:35)
Deliberate mistake: Rafiki is supposed to be a mandrill, but mandrills do not have tails. In the extended version DVD, there is a commentary by an animator who specifically admits that he knew that mandrills don't have tails (at least not like the length that Rafiki sports throughout the movie), but he put one on him anyway to make him more monkey-like. (00:02:40)
Deliberate mistake: At the elephant graveyard, little Simba claws Shenzi in the face. When Mufasa saves Simba from the hyenas, the cuts are gone, a few seconds later. [This was done intentionally, I'm sure, for two reasons. The first being, Disney doesn't let fresh scars linger on the screen too long. Secondly, during that same scene when Mufasa rescues Simba & Nala, he claws Banzai in the rear. To stress the point later in the movie, that severe scar is shown too, but only briefly, it too disappears because of reason 1. Still a "mistake", but there's why.] (00:21:50)
Answer: Lions are not like humans, even though Disney tends to make them that way. It's rare for more than one or two full grown lions to be in a pride. Other males are in "bachelor prides" until they win a pride of their own. It's likely that Scar or Mufasa sired Nala.
Brenda Elzin