Even before the conspiracy was discovered, Kievit was fired from his position in the "gecommitteerde raden", because he published a libelous pamphlet, entitled "Brief van den heer van Sommelsdijk" ("Letter of Lord Sommelsdijk"), in which he defended his brother-in-law lieutenant-admiral Cornelis Tromp's conduct during the St. James's Day Battle, disparaging lieutenant-admiral Michiel de Ruyter at the same time.