For now, as for TFL I'm going to say it's a few gun people subconsciously buying into the antis' arguments. Political correctness at work? I don't know.
How about quislings or plants? You many not accept the idea of individuals trolling for an agenda, but it happens in every election cycle. Posters sign up or go active after a long hiatus and explain why this candidate's vote or stance really wasn't pro-gun control or anti-2nd A. After the election, the poster goes dark until the next one.
We are seeing the same thing now, as the antis try to drum up support for gun control.