When Sayuri discusses the conversation between Dr. Crab and Hatsumomo with Pumpkin, Pumpkin says 'I sat outside the door, but I could still hear them,' then later in the description she says 'Then the Doctor looked queasy, like he didn't want to hear any more.' If Pumpkin was sitting outside the door, she couldn't have seen the Doctor's face.
When Chiyo apologizes to Mameha about the kimono; when she first bows both sleeves of her kimono are behind her arms but in the next scene when Mameha kneels beside her, the right sleeve is on top of her arm instead of behind it.
When Hatsumomo and Pumpkin are leaving on the night of Pumpkin's debut, neither Mother nor Auntie spark flint on their backs. A Geisha would never leave her okiya without this act being performed as it was believed it brought good luck.
When Chiyo/Sayuri and Pumpkin are listening on Mrs. Nitta and Mameha's discussion of Chiyo's future, and the camera zooms in on the girls' eyes peering through the crack in the door, Chiyo's eyes move very fast and you can clearly see Chiyo's blue contact, since it does not move with the rest of her eye.