Empirical observation #2: That student didn't contact her later including not replying to emails she sent afterwards.

There's also a direct consequence of empirical observation #2: The lessons could not continue.

Assumption #1: The student pretended to be sick. This student could have been actually sick. We have no evidence either way.

Assumption #2: Your definition of "genuine friend" is the same as the teacher's definition and the student's.

Assumption #3: Using the term "obviously" shows that you've assumed that I (or possibly anyone reading this) have the same cultural values and definitions needed to draw the same conclusion that you have.

I know I'm being pedantic and apologies if my tone comes across as condescending. I would normally avoid replying in these situations but when I put myself in your place I appreciate having the other person's perspective even if I don't agree with them because it helps me to clarify my communication in future conversations.