Keep in mind that ratings aren't based on any actual measurements of TVs being left on. It's all collated by a 'sample' of people (no more than 10,000) who represent the whole of Australia and write what they watch in their little diaries.
wittyfan's link shows Nine did break it up, but somehow we're meant to believe that almost half the people watching NRL GF switched off at the end of the game, while just 70k did so for the auskick.
All that tells me is that they're using accounting tricks. Because NRL final was decided well before full time, it's likely many people had already switched off before FT. But because auskick one was close, the 2 second spillover from fulltime into the 'presentation' portion of the broadcast meant people would've been liklier to say that they watched some part of the post-full time broadcast. In reality, probably half the viewers switched off in the few minutes following the end of the game, and certainly didn't hang around to watch the presentation.
It just goes to show that breaking the broadcasts down into segments is a way for networks to boost the appearance of major events in ratings charts, and it's sketchy.
