"Liar"? This choice of wording sounds like a quasi-religious attack. Like they're blasphemers or something, that dared misinform about capitalism.
No chance they could be right, or at least just misguided, instead of "liars"? Or that the subject being more complicated than a binary like "designed/emergent"?
Now, to the gist of it. Numerous human societies existed that weren't capitalist. In fact in many countries (of the last 2-5 centuries) capitalism was imposed along with colonialism, and otherwise they continued their ancient ways of living and trading. It is widely accepted that what we call capitalism (as opposed to mere exchange and trade, which existed since forever) was born around 13-14th century in Europe.
In any case, whether it was emergent or designed doesn't mean much. It was both: it was collectively shaped (emergent), by several influences, but it also had clearly designed elements (from contract and labor law, to central banks and monetary policy).
National law for one gives a very precise framework that molds capitalism in a certain shape in different countries, and that law was designed by actual humans with specific purposes and goals in mind.
And of course, something being "emergent" and that thing having "anthropomorphic" elements (if you refer to the second part of my comment) is not contradictory -- if that something emerged by human action within human societies.