I think the story could have been told with 1/4 the words. Suggests you are a bit OCD. Telling the FA more than once that they should not throw away a passenger's trash without asking, as well as saying multiple times that you weren't sure about the compensation supports this impression.

The other passenger should not have butted in. You should have been more gracious. You could have pursued the matter further after you finished your trip and cooled off a bit.

Just my humble opinion.

(And to all of you who had to copy the entire OP into your reply: over the top!)