As a Tasmanian, a couple of other things have occurred to me in regard to the disappearance of this young woman, Celine Cremer. The period in which she disappeared is close to what is known as 'mushroom season' in which Tasmania's magic mushrooms appear and grow for a few months.
This forest is especially well known for the presence of its unusual fungi, so the likelihood that the type of mushrooms required to have a psychedelic trip would be growing there during that time period.
I do not know if she was known to use these types of drugs at all, and I apologise for speculating about her character in this manner to those who consider it denigrating, but if Celine was looking for magic mushrooms during her walk then perhaps this might explain why she apparently inexplicably left the clearly identified track and mysteriously headed off into the bush, as revealed by the police through the records of her mobile phone pings.
As a visitor to the state, Celine would not have been familiar with which mushrooms she was supposed to be looking for and, such as is a common practice amongst those searching for this type of fungi, she may have been in the presence of a local who knew what the right kind looked like, since it's quite a dangerous thing to do, to accidentally take the wrong type of mushroom, many of them being extremely toxic.
These mushrooms tend to grow in 'patches' which people discover and then return to each year when they're in season, since places well frequented by the public, like the nearby sides of the track would most likely have been long ago 'picked out' by people seeking to experience the mushrooms and accidentally destroying the regenerative growth pattern of these pants by picking all of them from an area and thus depriving it of the crucially necessary spores required to seed next year's crop, hence the necessity of Celine and her guide to move away from the defined track.
I know all of this is mere gross speculation on my part, but should Celine have been in this situation then the proposition I've described is not outside of the realms of possibility. If you'll permit me this, then perhaps during this excursion 'off the beaten path' some type of terrible accident may have befallen Celine. Her guide, panicking and not wanting to get into trouble, (since possession of these mushrooms is illegal in Tasmania,may have not reported this incident in a self preservation effort.
I'm sure there are numerous other potential situations which might be possible and, keeping in mind being earlier discouraged from suggesting foul play as an apparently unsuitable option, in my defense as a response in the context of my 'insider knowledge' as a Tasmanian, if you look at the comments from other local Tasmanian people attached to Ken Mead's article in the Tasmanian Times, you'll see that my thinking is very much in keeping with what other locals also think, particularly those who've had experiences around that area of the state, which their comments confirm is very much as I described, an economically depressed area, mainly populated by ex-miners looking for some way of making money after the end of the mining industry and living in a culture not particularly caring about following the rule of law.
Amongst those comments the general consensus is that Celine's disappearance seems too inexplicably odd for it not to involve foul play. What exactly the level or the circumstances of which, I will leave at what so far I've detailed, (in the interests of not offending further).