Other mistake: Stitch watches 1958's "The Spider" on TV in a store's window. Some shots face the TV screen, and other shots face Stitch so we're seeing the TV screen's reflection. When Nani tells Lilo they'll meet at 1:00, in this shot facing Stitch the reflection of "The Spider" movie is properly backwards (note "mattress" sign), but two shots later the reflection of the woman screaming in that movie is in fact not reversed as it should be ("The Spider" scene timecode is 00:55:50). (00:28:50)
Other mistake: In the beginning of the movie where Baby Jim is talking about Treasure Planet, he crawls under the top sheet of his bed that has been folded half way up the bottom of the bed, and peeks out the bottom. That's fine and all but then his mother straightens out the sheet and covers him up. You then see that the part he just peeked out of was the folded part so he shouldn't have been able to peek out.