The coffee stain on the Klansman's rope is already dry after Larry spills on it.
The optometrist would only give atropine drops for a retinal test, not a simple correction test.
The shofar blower in the high holiday scene is said to be playing a shevarim teruah, but the player plays a single note, which is a tekiah.
When the clansman opens his new robe, the blood drop cross is clearly seen, but when he enters the rally and the Star of David is revealed on the back the cross is not there.