Another great story from Department of Logic.
In today's class we were asked to do derivations using First Order Predicate Logic. One of the problems was very tough and the proof went over a dozen steps. I was one of the first person in class to crack it, and Prof. C. Chakraborti came over to see my proof. After going through, she pointed out that I have made a mistake while applying the exportation rule, and hence would require modifications. After that, she went through the proof by Khushboo (who sat in a seat alternate to mine). When she finished reading it, she told "I was expecting this" and pointed her some error in her proof. When she left, I asked Khushboo what the error was and why was she "expecting it". She told that she had made a mistake while applying the exportation rule just like me, though her error originated from her class notes as against the memory failure in my case. Then, the whole incident dawned on me. The professor is used to seeing one person in a row doing the question, and all others copying it. She attributed the mistake made by Khushboo to this phenomenon and went ahead. Truly speaking, she committed a Causal Fallacy by wrongly attributing Khushboo's mistake to mine. Howsoever improbable this event may sound, it did happen, and thus exposed the fallacy committed by a professor teaching logic!
Moral of the story: Never attribute to malice what can be adequately explained by stupidity.