In A the 
before the middle note of the L.H. chord is placed clearly too low, which in this case could have been due to the intention of avoiding collision with the bar line. Fontana correctly interpreted the meaning of that mark in FC (→GE); however, in FE the sharp was initially ascribed to the bottom note of the chord, g
. That erroneous version got to EE1 and was then corrected through the addition of a proper both in the last phase of proofreading of FE and in EE2 (→EE3).
Compare the passage in the sources»
category imprint: Differences between sources; Source & stylistic information
issues: EE revisions, Errors in EE, Cautionary accidentals, FE revisions, Accidental below/above the note
notation: Pitch