That article seems to contain a lot of assumptions, I wouldn't place too much reliance on it. I don't know that there was any evidence that Bouvet made his first confession after torture - it was claimed he had attempted suicide and he never seems to have contradicted this even though he went back on much of the statement.
However, the article claims that the first lodging of the conspirators was at St Leu with 'Mme de Bonneuil', Bouvet de l'Osier's cousin, who was an agent of the French government and whose connection was kept out of published information. Now, is she by any chance the 'Michelle de Bonneuil' mentioned in the Roberts quote as a Royalist plotter? Or is this just a coincidence of names?
It just gets more complicated......