Duncan: I'm a Professor. You can't talk to me that way!
Jeff Winger: A 6 year old girl could talk to you that way!
Duncan: Yes, because that would be adorable.
Jeff Winger: No, because you're a 5 year old girl and there's a pecking order!
Jeff Winger: I discovered at a very early age that if I talk long enough, I can make anything right or wrong. So either I'm God or truth is relative. In either case, booyah!
Duncan: Interesting, it's just that the average person has a much harder time saying 'booyah' to moral relativism.
Abed: I thought you were like Bill Murray in any of his films, but you're more like Michael Douglas in any of his films.
Jeff Winger: Yeah, well you have Aspergers.
Answer: It was part of the plot that when the boiled yam was dropped it looked like it was stepped on (which it never was). So there was no way to tell the difference between the flesh being soft because it was boiled or because it was stepped on (in the show that is, I don't know if one could tell the difference in real life). Plus, the rest of the yam wasn't boiled, so there was no evidence the yam was sitting in boiling water.
Bishop73