He could have possibly been distracted or not paying attention during the teachers lecture. That's one potential reason, another is that he could have misheard or not have completely understood the lecture word by word, and missed a couple of words. He also could have not heard the teachers voice very well. They could have been speaking softly or silently or Roscoe might not be able to hear very well. There are some possible reasons why Roscoe had blank spaces in his notes.
