Catching a bug with duplicate comments

once took up the comments, I will insert my 5 kopecks.
I apologize in advance to Habr's technical support for not writing to the soap - I honestly started writing and realized that I didn’t know the exact reasons for what was described below, but I didn’t want to get you any extra letters.

So, today once again I caught a bug with duplication: you write the answer to some comment, click “Send” and see how some comments from other users have been duplicated. The first thought - “they give people the weight, they smack twice.” In fact, this is such a glitch, F5 humpback will fix everything in place.

My guess: the glitch only works when:
a) you first went to the topic page
b) updated not through F5, but the “update” of the habr - a small square hanging on the side of the page
c) after the update, several new comments have appeared
d) you wrote your / answered someone
d) got a bug

but at this stage I am not sure that this is the case. therefore, I propose in the comments to this post try to track how the bug actually manifests.
Although not deadly, it is better when it is not :)