https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...
(1) the internet is, to a first approximation, wrong about everything - so while posting "Wrong" tells us that you disagree with the GP, it doesn't tell us anything about who's actually right;
(2) shallow dismissals like "Wrong" have a degrading influence on the threads - they don't just encourage others to post more of the same, but worse. Basically, either your comments are contributing to improving the discussion culture or they're worsening it - there isn't really any level ground.
You can overcome both (1) and (2) by respectfully and substantively explaining why the other commenter is wrong. Then we all can learn something. Maybe (hopefully) even the other commenter can learn something.
If you don't want to do that or don't have time, it's better to post nothing than to just post "Wrong". That way you don't have a negative impact a la (2), and per (1), the internet is wrong about everything anyway, so you're basically just leaving things the way you found them.
Consider that HN has ~5 million MAU and that a comment without clarity is confounding many people. Writing and communications generally is a service to the reader not the author.
If you don't have time to look up the precise source, a note along the lines of "I don't have time to find the direct link ..." or "I recall but cannot source ..." would help, along with where generally is the best direction to start looking.
Returning to that comment later to clarify/expand is also useful.
(I do both of these fairly often. And have written ... 612 ... comments with footnotes and references on HN to date: <https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...>.)