Plot hole: It took Ender only a few hours to unravel a mystery that 3 generations of highly educated and skilled xenologists and xenobiologists were unable to do. Pipo, of the first generation, was restricted by the rules imposed on him by the congress and he found out the truth but died because of it. After that Libo should have simply asked the piggies what happened and should have digged into the piggies' reproduction system, like he should have done in the first place as that is his job. Both Libo and Miro and Ouanda broke the rules so they shouldn't have had a problem with asking the right questions. They weren't afraid of the piggies either, loved them even. Libo would have had the answer to the reason for the death of his father and understood the piggies in a week, even though Novinha had hid the original data. If not him Miro and Ouanda would have had plenty of time to figure it out as well, just by asking questions. They would have learned a lot more about the descolada virus decades sooner as well, giving them more chance to combat it successfully.