I understand the lack of professionalism and self control here, but I think to call it rape is to demean the nature of actual forced rape cases, which are utterly vile and reprehensible. This was ultimately consensual, whether or not the law recognizes her as an adult. Some places in the world recognize much younger girls as adults, and certainly in past generations much younger girls have been married off without any will of their own to factor into it. Here in Oz the consensual age is 16, so really the only foul from this end is the fact that the teacher may have been seen to have abused a position of power.. though I doubt that's the case. From the account of things the girl actually came to him, the fact that he was a teacher seems incidental. I think the real issue is the weak-willedness of being tempted with something fresh and young and succumbing to it, which many men are susceptible to.
Most 16 year olds I knew 7 years ago were absolute sluts. It sort of comes with the age. I'm not particularly up for getting caught in all the melodrama. Many girls my age are still sluts, and many of them have slept it up with guys much older than they. 16 or no, many don't mentally mature past that point whatsoever. These laws, restrictions, in many ways are arbitrary, reflective of where society is at TODAY and not where it has been, nor has yet to go.
All that aside, a 40+ year old dude sleeping with 16 year old chick is pretty fucked up, but to call it rape in this particular case I think is a bit of a stretch, and indicative of the law interpretation becoming a bit overzealous.