That argument would be coherent if not for the fact that in this case, the commenter had scrolled past one unsupported set of statements, accepted them, then challenged the other set; that's not reasonable.
Accepting something without evidence and only challenging things that disagree with your evidence-less beliefs is the exact opposite of even-handed.
> scrolled past one unsupported set of statements, accepted them
And what tells you that they were not already aware of the evidence for those statements from prior knowledge? If so, then they would naturally only ask for evidence for the claims for they are not yet aware of the evidence. No need to re-ask for that.
Obviously I don't know whether they had such knowledge, but you seem to assume they didn't and are criticising them for this.
Because as much as you attempt to weasel around it, we're not talking about a spherical hypothetical in a void. We're talking about a specific event, for which no such evidence has been released.
Accepting something without evidence and only challenging things that disagree with your evidence-less beliefs is the exact opposite of even-handed.