Factual error: When Esposito revisits the murder scene, he asks Morales whether he would prefer the culprit to receive the death penalty. Morales answers that he would not, claiming that to doze off and fall asleep (hinting at execution by lethal injection) would be too good for the man who raped and brutally murdered his wife. Execution by injection has never been practiced in Argentina - where the last execution was carried out in 1916, by shooting - and was legally enacted only in 1977 and practiced the first time in 1982 (in both cases by the state of Texas). Thus, it seems anachronistic that anyone would equate the method with capital punishment in 1974, when the scene is set.
Other mistake: At the end, when Esposito is looking at the piece of paper where he wrote "Temo", he put that paper over the pages of the novel and we see one of the pages. In the third line there is a handwritten "A" over an existing "a" between the words "pAsó" and "ese." In the fourth line there is an existing "a" that's not overwritten in the word "la." But the typewriter had a missing "a", so there should be none in the text.