When we see Ella mending her dress for the ball, the camera pans down to reveal the mice making her shoes. When she gets on the carriage later, her shoes are the dirty blue ones she's always been wearing.
When the pumpkin starts to grow inside the greenhouse Cinderella and the fairy godmother are pushed against the glass while they're scooting together; however when they leave the greenhouse, they exit from opposite sides of the door, meaning one of them would have had to scoot around the greenhouse's circumference to exit.
When Ella's father leaves on his last business trip, the pair of horses at the carriage he leaves in has no white on their legs. As the carriage pulls into the road (and the camera pans back to Ella), the horses each have four white legs (and are probably the same pair of bay hackney horses that bring Ella's father home in the opening scenes; each horse has a wide blaze on its face and four white stockings). This same pair of very distinctive horses also appear briefly at the beginning of the king's ball, when everyone is arriving.
When the lizard becomes a coachman he has a forked tongue, but while waiting for Ella (who's fleeing at midnight) he catches a fly with a long pointed tongue.
Cinderella's glass shoes magically appear on her feet, obviously under her dress. When the magic has finished she looks out in front of her dress at the spot where her old shoes were and asks, "They're made of glass?".
When the painter falls, we see his palette on a right angle. The tin on the palette would have a paint thinner inside; however, nothing falls out of the tin when he falls. It would be impossible to use his paints without it.
The fairy godmother says that her enchantments lose their power after midnight. Indeed, when Cinderella runs away from the ball, all magic items (mice to horses, pumpkin to coach, mother's dress to fancy gown, lizards to servants) are changed back into their previous shape. There is no reason given why the magic shoes should remain in their enchanted state of glass. Though it could be argued that because she took off her old shoes and the glass shoes were created on her feet, they would not be transformed back like everything else. They were created, rather than transformed: such as the pumpkin being transformed into the carriage and the pink dress to the blue dress.
When Cinderella is riding her horse in the forest without any saddle or bridle, there are a couple of close-ups where we can clearly see her holding reins.
After the Ball, when Cinderella chooses to write down all that had happened, she picks up a pencil. She was writing with a 2HB wooden yellow pencil with a pink rubber eraser and a green and yellow metal eraser holder.
The shot of Cinderella getting out of her carriage after arriving at the ball shows the carriage wheels to be metal. If the setting is set during the early part of the Victorian Era, then the wheels should have been wooden, since the metal wheel was not invented until 1870.
At midnight, you see the Full Moon low on the horizon. The Full Moon would only be low on the horizon at dawn or dusk. The Full Moon should have been high in the sky at midnight.
In seeking an object to turn into a coach, the fairy godmother says she "doesn't usually work with squashes...too mushy", but she had just asked Cinderella if she had a beef tomato, which is much more delicate than a pumpkin.