The brutality of the Guatemalan military does exist, based on newspaper and TV reports. By now, students should be aware that what is in print or, for that matter, on the Internet is not gospel.
Bias exists in anything written, even the best analytical report.
I am not sure the Nobel committee should have given the prize when later inaccuracies were pointed out. It is their responsibility to check on the sources and check again. The Middlebury anthropology professor should be commended on doing the 120 interviews to point out inaccuracies. We have to be careful in an academic environment not to present just the politically correct viewpoints of oppressed parts of the world. Students need all viewpoints to help them learn how to think.