(at around 3 mins) When Po wakes up in the beginning of the movie, a throwing star falls down and lands on the floor. Later, when he tries to throw it back up on the wall, the original throwing star is still in the wall.
(at around 12 mins) When Po tries to use the bamboo to vault into the ceremony, he makes a big crack in the wall - however, this disappears right away as it is never to be seen again.
(at around 32 mins) During Tai Lung's escape scene, he tosses 4 spears into the air. When he jumps up, he kicks only 3 spears, but 4 are shown crashing into the prison wall.
When Po is fighting Tai Lung, Po hits Tai Lung right into a house, destroying a part of it. Yet after he defeats Tai Lung and the villagers come back, the house is fixed as if it never happened.
(at around 21 mins) After Po accidentally breaks the Urn of Whispering Warriors, the pieces move around on the floor.
During the end credits, each character appears with their actor and Chinese name. The Chinese character for Tai Lung is missing a dot, making it Da Lung instead.
Oogway says: "Look at this tree, Shifu. I cannot make it blossom when it suits me nor make it bear fruit before its time." However, the peach tree is both blossoming AND bearing fruit which is impossible for a peach tree. They blossom first and then bear fruit much later in the season.
Tai Lung, a snow leopard, is at times heard emitting a tiger-like roar - a sound snow leopards are unable to make due to their lack of a larynx. Since this is a fantasy where snow leopards and other animals talk, wear clothing, and have other anthropomorphic abilities, this is unremarkable.
When Po finally gets to eat a dumpling but instead yields it to Shifu, Shifu throws it a short distance behind him and the clinking of a bowl can be heard, even though the dumpling bowls are now much farther away.
When Tai Lung confronted the Furious Five, he found out that the Dragon Warrior's name was Po. But when they meet each other, Tai Lung forgot Po's name, and asked, "Who are you?" - Tai Lung learned only Po's name, he never knew what Po looks like or what animal he is. Like everybody else, he didn't expect the famous Dragon warrior to be a panda.