No, the original statement is a fabrication so the conclusion is a non-sequitur.
The original statement from rubycodez was as follows:
we cannot ascertain the temperatures of past centuries with enough precision to make any such study nor claims
That's not a fabrication. That's just wrong. Calling it a fabrication bestows too much grace on it.
Sadly, the anti-science (and particularly anti-AGW) crowd has no shortage of wrong statements, because unlike scientists, they are not tethered to facts.
We may not have direct records but that's not what the paper presents. Science is not always able to have first-hand accounts, but only indirect data sources, and yet we rely on it for a shocking amount of findings. Will you start dismissing those as well because they don't suit your agenda? Because an agenda it must be, for you to make such unreasonable demands and yet draw unrelated conclusions from them, while trusting other science based on similar methods.
This. Claiming that indirect evidence does not count is a desperate, sophomoric attempt by the anti-science crowd.
Recall the recent debate between Bill Nye and Ken Ham on the theory of evolution. One of Ken Ham's favourite strategies was an attempt to make a distiction between "observational" science and "historical" science, with the latter being invalid in his opinion. How often did we hear him say "you don't know, you weren't there" in response to indirect evidence?
What if, after the debate, Ken Ham had walked to the parking lot of his museum and discovered that the driver-side front fender of his car was damaged, with debris from his front driver-side headlight strewn on the ground? He would no doubt conclude that someone hit his car while he was parked there. But not so fast, Mr. Ham. Let's apply your own standards of evidence: You don't know. You weren't there.