I thought there were systems designed to effectively negate users that submit too many misleading posts.

Your parent post isn’t suggesting it’s always the same user submitting, just that users submit a lot of posts from this person.

Can’t say I agree, though. I don’t recall ever having seen one of his posts on HN, and a cursory search suggests they’re not even upvoted that much. Highest I found was under 30 points. But my methodology is flawed, as I basically searched for the name.