There's no such thing as a "false flag", just as there's no such thing as a "false upvote". Fradulent? Abusive? Sure. But true/false implies these things are objective.

While you are probably technically correct, remember many here are not native English speakers.

Given the quotes it seems poster was aware that the word wasn't perfect.

I'd try something along the lines of "I guess the word you are looking for here is fraudulent or abusive".

That’s kind of passive aggressive in my opinion (I believe you’ll disagree, and that’s fine), I’m unlikely to adopt that communication style.