It must have been Chopin who removed the natural to the 5th quaver while proofreading FE (→GE,EE). This is the second correction at this point – in A one can see that the next note was also changed, most likely from g
3 to f3. Therefore, the last two notes of the first half of the bar were, in chronological order, a3-g3, a3-f3, and a3-f3.
Compare the passage in the sources »
category imprint: Differences between sources; Corrections & alterations
issues: Authentic corrections of FE, Main-line changes
notation: Pitch
