Both 
marks in these bars have clearly different arms in A – the top arm begins in the middle of the bar, while the bottom one – on the 2nd beat. According to us, it is the top arm that should be regarded as reliable, since it was written first. This is how those marks were interpreted in FE (→EE) and the latter also in FC (inaccurately reproduced in GE). In FC (→GE) in b. 15 Fontana averaged the length of the arms.
Compare the passage in the sources »
category imprint: Graphic ambiguousness; Differences between sources
issues: Inaccuracies in GE, Scope of dynamic hairpins, Unclear hairpins in A
notation: Articulation, Accents, Hairpins