When Jim-Bob throws the paper airplane in the store, it lands between two stacks of cans on the top shelf. When he does to get it, it is suddenly all the way behind one of the stacks.
The Walton's have a bathtub inside, but both Josh and Jim-Bob take baths outside in a metal tub.
Olivia starts to teach Josh the alphabet because she assumes he can't read, but John had already seen Josh read the 'Sheriff' sign outside Ep Bridges' office. It makes no sense that John would not inform Olivia of this.