Don't worry about that. The problem is not so much that it got submitted-- all kinds of stuff gets submitted-- but that it got so many votes so rapidly. Could just be a random statistical outlier, come to that.
Are you looking at any other information about how this story got voted up so fast? I haven't looked at the HN code at all, but I wonder if there is anything sophisticated for stopping people from colluding and spamming. Do these accounts come from the same geographic area? ISP? Do they vote like each other in the past?
Vote-weighting doesn't even really seem like it's going to be the solution to the problem. Well, it might end up being the solution if you give a great deal of weight to trusted accounts, but you might in the end discourage new users from contributing.
I think maybe you consider attacking spammers head on. I really don't think the problem is a bunch of newbies up-voted this story. HN is just easy to game.
You see spam on HN, but it is hard to believe this is a case. The story about profit per company had been up for about 10 hrs by the time I posted. A respected blogger with impeccable tech/startup credentials (founder of Tabblo acquired by HP) posted a thoughtful reply showing how poor PPE was at some large tech companies relative to other companies. It is related and interesting, if a bit mislocated.