I decided to load my earlier save and do it again (time goes by when you repeat the same quests ), anyway I choose the aggressive response to Pallegina, and aggressive towards Verzano. I killed him, the lady in the "sombrero" hat thanked me and when I left the company THROUGH main entrance Pallegina was there, everything went good. Pointed out all of my choices here, so maybe try doing the same and it might work for you, as it did for me. I guess you might also try diffrent approaches, and when they don't work just TRY AGAIN until you have it.