But with two competing claims, and no easy way to check ground truth, you absolutely ask for citations from both sides. There's nothing rational about uncritically accepting the narrative you heard first.
Demanding evidence from one party while accepting the word of the other is not even-handed.
It's not. I have no idea how you got there.
The right thing is to seek evidence for both perspectives. This is ironically not rocket science. Don't accept any viewpoint just on say-so, but especially don't pretend to sneering objectivity when you do so.
> 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".