Ask HN: Has anyone analyzed the ratio of upvotes to comments on HN stories?

I just noticed a story on the homepage with something like 90 votes and 300 comments. That's a bit unusual, as normally for popular stories upvotes slightly outnumber comments. I could see two possible situations where a story gets more comments than upvotes, both of which suggest a controversial topic. First is if the topic encourages long comment chains; even if everyone who comments also votes, multiple comments by the same user could result in this pattern. Second is if the story engenders negative reactions, causing people to comment but not upvote. I'm curious though whether others have noticed these patterns, or have any other related thoughts.