In the case of such a small element as an augmentation dot, put in an atypical place, a double, independent oversight cannot be completely ruled out. However, it seems more likely that Chopin added this dot in the last stage of proofreading FE, after the copies serving as the bases for GE and EE had been sent.
Compare the passage in the sources »
category imprint: Differences between sources
issues: Errors in EE, Errors in GE, Authentic corrections of FE
notation: Rhythm