When the Prince and Lionel are testing the glass slipper on all the women in town, the scene shows a long line of feet waiting, followed by a few feet trying on the shoe. The final foot before the prince leaves the house frustrated appears to be a man's foot as it is much larger and the legs of the person are not shaved. The man is also wearing a white flip-flop on his other foot which is again uncharacteristic of all the costumes in the movie.
During the scene in the palace hallway, the Prince and Lionel are talking while Lionel helps the Prince get dressed. When the Prince goes through the passage to the room his parents are in, it's obvious he is not dressed well, with only two shirt buttons done up, cuffs undone, shirt untucked, etc. But when he meets his parents, he is perfectly dressed and neat.