The Libertarian Loophole is exemplified by their position on public transportation, they don't oppose public transportation they just don't want the government doing it - let the free market provide it if the public want it! Except, of course, the free market demands a quick high return. Railways by their very nature are a long term low yield investment generating a return on a scale of 30-40 years, not by the next financial quarter. Something the public can and will accept for public infrastructure. But not business interests. So what the libertarian argues for is a situation where economic strictures ensure it will not happen but they can insist they do not oppose it.
Libertarians are either phonies, posturing, or completely ignorant. Even the hyperliberal/hypercapitalist pre-WWI Bourgeoisie knew they needed the state because it was the only entity capable of protecting their investments and their property, as well as of building the infrastructure and selling concessions on them (e.g. railroad, to take your example).