Despite the fact that the a2-a3 octave is possible as far as the sound is concerned (cf. the Prelude in F minor, Op. 28 No. 8, bars 6 and 20), Chopin's mistake seems to be almost certain here, even due to the pianistic issues. The conclusion is confirmed by Chopin's proofreading performed in this place in FE (→GE,EE).
Compare the passage in the sources »
category imprint: Interpretations within context; Differences between sources
issues: Terzverschreibung error, Errors in the number of ledger lines, Errors of A, Authentic corrections of FE
notation: Pitch