When the first blind man arrives home, he says he lives on the 14th floor. After his wife arrives you can see some trees through the kitchen window. Those trees should not be there.
The pistol used in the movie appears to be a snub-nosed revolver, typically holding between 5 to 10 bullets. The number of rounds fired off without any indication of reloading is closer to 15 throughout the "Ward 3" standoff.
When the Doctor's wife is boiling water, there should not be any sound, because the kettle does not have a whistle cap on it.
During food distribution, when the "king of ward three" points the gun at the doctor's throat, we distinctly hear the sound of the hammer being cocked, however one can clearly see it's not cocked at all.