Other mistake: After talking to his own mirror image when guarding his house from the "Heffalumps and Woozles", Pooh turns around counter-clockwise. This should mean that his mirror image would turn clockwise but it ALSO turns counter-clockwise. (00:35:55)
Deliberate mistake: Several times during the movie the narrator explains what happens while the book flips its pages. During this, every page is identical to the last one so the animation has simply been copied/reused to save time and money.
Continuity mistake: When Christopher Robin picks up Eeyore's tail, he and Kanga are several feet away. But in the next shot they're right next to the donkey. (00:07:35)
Answer: Holloway could have continued voicing Winnie the Pooh, but by that time he was in his 80s and felt he could no longer effectively use his voice for the character as he once did. He chose to retire from the role.
raywest ★