Being to select the chunk of text you interested would probably solve this issue. I wonder how Readability "selects" the "relevant" part of the page. Maybe it is just a smart heuristic about what the user want ;)
Come from HN => must be a PG fan => Just display "PAUL GRAHAM" => Go back to HN and vote
Reloading the page 'disable' the service, even if it is far from ideal.
I really like it though. I was looking for something similar for years.