they butchered this scene in the dub, because in the dub, the 3 notes make a complete sentence and thus make sense

in the original Japanese, the 3 notes seem like they don’t make sense because of the numbered order on them, so when L introduces the fake 4th note, it “completes” the sentence, catching Light off guard because he never considered a 4th note because he knows there is only 3 because he wrote them

in the dub, it doesn’t make sense Light should even suspect a 4th note because the 3 notes together make sense because of the way English works vs Japanese

in other news i have forgotten what grass feels like