Was Sauli a ‘good and innocent man’ or not? Was, there, indeed, a plot at all? Some think that there was and that those implicated were guilty, to whatever degree. These include contemporary observers such as Paris de' Grassis (but with reservations about the involvement of Riario, which are shared by Sebastiano Branca di Tedallini), Cornelius de Fine, Paolo Giovio and Francesco Guicciardini.

Others deny that there was a plot. Alfonso Petrucci's Portuguese manservant regarded Petrucci, Sauli and Riario as innocent victims; in about 1526 Jacob Ziegler blamed everything on Cardinal de' Medici. Girolamo Garimberto, a sixteenth-century writer, believed in the ‘innocence (of Sauli) which still survives today in the opinion of many’, an opinion shared by some later and present-day commentators. The group's most convincing advocate is Kate Lowe, who discovered an account of the plot in the Vatican Archives allegedly written by the cardinals' supporters.

Arguments for the existence of the plot

The diarists de' Grassis, Tedallini and de Fine were not the only witnesses to the unfolding of events who believed in what they saw and heard. The orators present in Rome also believed in the plot – namely Costabili, Minio and the Portuguese ambassador. Their attitude was eventually shared by the Genoese. Although initially the Genoese government had found it diffi- cult to believe Sauli capable of such a thing, in none of the letters from Tommaso Cattaneo is there any indication that he, present in Rome and in close contact with the Sauli, considered the plot to be a fabrication and Sauli (and Riario) to be innocent.