According to the Reuters news agency, citing off-the-record interviews with people closely involved, the deal whereby Kenji Fujimori would lend his support to Kuczynski in return for the pardon for his father was arranged back in September last year. This was well before the impeachment vote in which Kenji’s supporters saved the presidential bacon.
According to Reuters’ sources, a September meeting in the presidential palace led to a sequence of negotiations to pave the way for Fujimori’s release. Among the obstacles to this was opposition from the then justice minister Marisol Pérez Tello, replaced in a cabinet reshuffle that month by the more pro-Fujimori Enrique Mendoza.
Announcement of the pardon was apparently scheduled for the third week of December, but it was the impeachment that finally triggered the deal just before the Christmas break.