This happened to me too. I posted an article on my blog and it got on HN's front page. It was about how people have to stop sending .doc files as attachments via email and to use something like .pdf instead. (my article is here: http://maxmackie.github.com/2012/03/19/Stop-distributing-.do...)
He posted about a week after me. I didn't really do anything about it, but he could have at least mentioned where he got the idea/information. Incompetence.
I wrote the article you're complaining about, which is actually mainly about making hybrid PDFs. I did not see your article, let alone copy it; I would have linked to it if I had. I have been working on that piece for a few months off-and-on and pitched it as a "lightning talk" at FLOSS UK Spring 2012 in Edinburgh beforehand.
More than that, I was a manager of the team that created the hybrid PDF feature in OpenOffice at Sun, and have been advocating avoiding editable attachments for years - the earliest I can find on my blog is http://www.webmink.net/2003/07/feature-creep.htm but I am pretty sure I was advocating it before.
The web is a big place where there are often people working on the same ideas as you (which is why software patents are a travesty), and I recommend avoiding accusing people of incompetence without a little more research.
Actually he presented this at a conference in Edinburgh called FLOSSUK a while before he wrote the article, and since he's one of the people who was involved in making OpenOffice happen he probably knew about it a long time before you did :-) These things happen,
A couple days later, this guy wrote about the same exact thing, bringing up the same exact arguments as I did (his link: http://blogs.computerworlduk.com/simon-says/2012/03/the-magi...).
He posted about a week after me. I didn't really do anything about it, but he could have at least mentioned where he got the idea/information. Incompetence.