I think you might need to more clearly define the problem you are trying to solve. You start off talking about a specific case of users commenting before they have finished reading the article.
I don’t think measuring engagement with other comments nor other articles on the same site really helps with that.
Also, are you trying to persuade the crash-commentator to give up or to go back and read the article?
If the crash-comment gets submitted, and you are somehow able to identify it as such, what are you hoping to achieve by flagging it to other commentators?
The root of the problem is that article headlines are intended to provoke a response from people who have not yet read the article. The decision to crash-comment may well occur before the reader even clicks on the link.
Personally, I would add a “Jump to Comments” button at the top of the article to allow people to self-identify. Any subsequent comment is then visible only to its owner. They get to vent but no-one else has to listen.