Overly concerned for INFJ friend

Today a classmate from college failed her subject and has to repeat the whole year and today was the last day to pass and because she didn't make her presentation, my INFJ friend did her own one, but she totally forgot that her classmate also had one and it took the whole lesson. At the end of the lesson the classmate asked about her presentation, but the lesson was already over and she didn't tell us, so she failed automatically. My INFJ blamed herself for not giving this classmate this chance but I don't see it this way and I had the impression that she was thinking really long about it. Now I called her just to check on her and she said that everything is fine and there is nothing to worry about. I feel like an idiot doing something unnecessary. Do you think I should have just left it instead of playing an annoyance?

P.S. Sorry for this long senseless post.

~ A stupid ENFP