Surely if Russia was manipulating BBC reporting it would be note-worthy as well no?
Even on HN (and sometimes, especially on HN).
There are some divisive topics that are less prone to flame wars on HN vs. other discussion platforms, but those are fairly limited, and often not political (in my experience).
This has already be used on HN to essentially silence any serious reporting on climate change. Anyone technical with an interest in data will find most climate change related studies interesting, but a small minority of people who are fearful of the consequences will make sure to create an issue and shut down conversation, organically getting posts "flagged".
I think by playing the brinksmanship card of "there can be no level-headed discussion" you inadvertently discount a lot of perfectly coherent and important digression, on both sides. If every HN thread resorted to this logic, nobody would want to use the site.