You are free to define yourself as you please.
But there is no point, just like there is no point arguing with someone who insists blue is brown.
If you can't agree on common definitions, a logical and educational debate is impossible. And this author is willfully obfuscating and saying blue is brown. His premises can simply be dismissed because he's blatantly lying about libertarianism.
I just dismiss this and move on. His whole article reads like someone who had to give a book report and simply skimmed his Cliff's Notes. It's very apparent he doesn't know the subject well enough to make a coherent or credible case.