Yeah. But I belive there is a significant jump from the 1st rank and the rest of the ranks. I think luck comes into play. For subjects like English, you need to get a marker that conforms to your view, for subjects like Maths, you want markers who can mark properly.
For subjects like Maths, one or two marks can separate people getting a state rank and people who don't. And since I have a poor hand writing, I am quite certain that I could have lost marks if markers aren't satisfied with my writing (e.g. my 8 looks like 2 0s). And that's where my luck comes into play even though I am certain I got 120/120.
And rememeber, the phone call is only for the top rankers. Not getting a phone call today or on whatever date doesn't mean you didn't get a state rank. Who knows? You could have got state ranks for every subject, but not just first and it happens quite commonly thesedays when competition is quite fierce in basically every subject.