Being substantive means replying to the actual argument instead of questioning the credibility of the person who makes an argument.

The OP started without substance while trying to smear HKers fighting for their freedom from the authoritarian CCP so why attack the person who highlights the suspicious nature of the accusers account? We live in a world of ever increasing propaganda. Pointing it out is as substantive as it gets. If anything your message is better suited for the OP. They did exactly what you are flagging the child comment for.

If you think OP is smearing, you can refute his argument with facts and flag his comment. It’s a human bias to think someone whom we disagree with has a malicious agenda. Democracy can survive the worst oppression, but will perish if we fail to conduct civilized discussion and start accusing and labeling each other when we disagree.

Calling a liar a liar is better use of time and energy than tirelessly repeating facts ad nauseam.

I know we all have an impulse to take the easy path. But please think about what if you happen to be wrong, how a person would feel if he’s labeled a liar/paid troll for having an account that looks suspicious to some, and what meaningful discussion we can have if we just call each other liars?

2nd order lies are still lies.