Sorry what exactly does his tone, whatever it may be, convey about whether or not the study in question was done well? I know it's difficult for some people but if you want to do science you have to focus on the facts. This tactic of mentioning the tone ("scathing") has only one purpose in a scientific discussion and that is to throw chaff into the air and derail the conversation with nonsense. Other examples of this are: you pronounced a name wrong! that's not my pronoun! "othering"! racisnogynism!

And yes a posited fact is also known as a claim.