When the flock of Spearow swoops down to attack Ash after he tells Pikachu to get in his Poké Ball, Ash's hat is shown facing forward despite it being turned backwards earlier.
During the infamous scene where Pikachu speaks English, it claims it doesn't like going in the Poke Ball because it doesn't want to leave Ash's side. This makes absolutely no sense, as Pikachu didn't like going in the ball even back at first, when it didn't even like Ash yet.