I got there because somebody asked for evidence for a certain viewpoint and you seemed to push back against this ask by suggesting that if you ask for evidence, you need to demand it from both sides. As if somebody failing to do that doesn't entitle them to any evidence from anybody.
> Don't accept any viewpoint just on say-so
Exactly. That's why they asked for a citation. A response providing such citation is more appropriate than essentially saying "well you didn't ask for a citation from $other_side either".
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.