I can see the point. "Freedom of speech" does NOT mean you get to make an unscheduled presentation at someone else's rally. Video Here. So, holding a sheaf of papers and shrieking "freedom of speech!" doesn't make much sense, when you are on private property reserved and contracted for by someone else.
Still, every time I think of John McCain, I do want to go do something that might get me arrested for saying bad words in public. So I don't blame the "libertarian," either. We don't think much of John McCain.