It really seems more like they didn't read the second line though, since there is nothing in how that comment is phrased that acknowledges it, and since that sort of comment-without-reading is extremely common especially for topics with political significance.

The standard way is to clarify your answer by rephrasing the question rather than only saying "no" or "yes".

So in this case maybe that could have been done by saying it like "No, they won't do it properly," but if you want to communicate that you have read the whole thing you're responding to you basically have to do this, because it is extremely reasonable to assume it was not read if there is no indication.