I am saying "X is a claim in a highly technical field that most of us lack expertise in. Y making that claim has a made large factual errors in prior publications, and his claims run contrary to the vast majority of his peers."
Sorry if you miss the nuance in my point. People also have referred to this concept as "taking with a grain of salt" or "heuristics".
Now, outside of arguments over semantics, the link article is lousy and the interpretation over what the lousy article claims by the great-grandparent post are incorrect.
The TL;DR of the linked article is: "They should have used data from another sensor, too. Based on 5 months of overlap, I'm going to assume I can just adjust the other sensor's data and use them in a single trend. Even if you accept that, I'm going to use a linear regression in this new cherry picked range, after making a big point about the nonlinearity of the underlying data. Even minimizing it the most I can, it still shows a 40 year trend of 3 mm annual sea level increases."