The motives behind Giovanni's submission to the Opera were not
perhaps the purest, especially since there was no basis for his claims. The
shells, as built, conform exactly to the specified quinto acuto profile, and no
corrections appear to have been necessary at any point during the
construction. The fact that Giovanni was so mindful of his own
reputation ('I shall be excused and blameless'), as well as so obviously
resentful of the fact that Filippo was 'well paid and compensated' for his
work, leads one to suspect a motive of jealousy.