In the first communique in which the SSPX announced the election of Father D. Pagliarani as Superior General, we could read:
The 41 capitulants will proceed tomorrow with the election of the two Assistants General, for the same mandate of 12 years.
However, Rorate Caeli leaked, on that same day of July 11th, that the Assistants would be Bishop de Galarreta and Father Bouchacourt:
For his part, the well-known Vatican specialist Andrea Tornielli also leaked the same information when he declared, on that same July 11th:
Tomorrow, Thursday 12 July, the Chapter will proceed with the election of the two new Assistants to the Superior General. Unless there are last-minute surprises, they will be Bishop Alfonso de Galarreta (one of the four bishops consecrated by Archbishop Lefebvre without a mandate from the Pope in 1988, act which provoked a mini-schism and the excomunication which was revoked by Benedict XVI in 2009), and the Superior of the French district, Father Bouchacourt.1
The news having been leaked, the SSPX released its second communique, announcing the election of the Assistants.2
All this implies that the decision to elect Bishop de Galarreta and Father Bouchacourt was taken by someone before the Chapter had proceeded with the election.