alleged symmetry in a study of hate in Israeli and Palestinian textbooks

"It found that extreme examples of dehumanization and demonization were “very rare” on both sides. The few examples given included one from an ultra-Orthodox textbook describing an Israeli settlement established on the ruins of an Arab village that “had always been a nest of murderers.” A Palestinian language textbook included a reference to “the slaughterhouse,” explaining it as the nickname prisoners had given to an interrogation center “due to the brutality of the interrogators.”"  This passage in my mind is enough to discredit the entire study and to expose its Zionist premise.  There is no symmetry in the two at all: the first one justifies genocide and calls the entire inhabitants of a city "murderers".  The second one refers to a real Israeli torture center which was nicknamed by its victims as a "slaughterhouse".  Where is the symmetry?  Where is the logic? Where is the outrage?