I, Rigoberta Menchú
Menchu, a K'iche' Maya woman, testified to the systematic genocide of Guatemala's indigenous peoples by the military: the murder of her family, the destruction of her community. Her testimony (recorded and edited by Elisabeth Burgos-Debray) became the most important document of Latin American indigenous rights and won Menchu the Nobel Peace Prize in 1992.
Later fieldwork in Guatemala established that several of the book's central scenes, including her brother's burning, happened differently or were witnessed secondhand, and that Menchú had more schooling than the text admits. Defenders answer that testimonio speaks for a collective. Maybe; but the book presents itself as eyewitness, and that frame cracked.
The case for it and the rest of the canon open with Pro.