This is how labelling works in MASS market manufacturing - I am a fashion designer with years of experience in the UK. Not sure if this is the same in Australia, but I would guess so:
1) Designer (who works for a manufacturing company) designs garment and sample is made in the design studio and put in the showroom. The label put in at this stage is the manufacturing company's label, e.g. 'Young Fashion Manufacturer'.
2) A store group, let's say 'Big High Street Store', visits the showroom and wants 1000 of these made, so the manufacturing company gets a factory to make these. This may NOT be their own factory (as in owned by them) but is likely to be one they work with regularly. 'Big High Street Store' provides their OWN labels to go into the garments - this can be 'Big High Street Store' or another identifiable label associated with the store, let's say 'Young Miss'.
3) The factory making the garments will sometimes try to get more garments out of the fabric provided - by being economical with the layout when mass cutting. These EXTRAS are called CABBAGE, and neither Young Fashion Manufacturer or Big High Street Store know about these extras, which will be sold at outlets such as market stalls, on the cheap with a label that the dodgy factory uses - this can be a label the factory gets from anywhere, off the shelf, or could even be a label from another manufacturer they work for. Essentially any label is needed and an unscrupulous factory will put any one in so that the goods can be sold off.
So with the above scenario, the same garments can exist with the label of the manufacturing company, the big store, and any label used by an unscrupulous factory. That's THREE different labels. Whilst the first 2 labels are relatively easy to trace back to source, the last one is very difficult to trace back, and that is deliberately so, making it hard to trace dodgy trading on the factory's part. The factory can deny all knowledge.
So essentially, what I am saying is that if the labels are not recognised as a manufacturer's or store group's, then it is likely that these garments were passed from dodgy factory to dodgy stallholder. The source and outlet may never be traced as the stall trader would not own up to being guilty of buying stolen goods (as essentially the fabric was not owned by the factory).
The above is my own opinion based on my own experience of the mass market in the world of fashion. (An alternative is that 1 and 2 are the same company so that cuts out one label, but essentially, the factory stage is where I can see a problem in identifying the source and outlet). I saw some of my own designs on a market stall once, with a false label in, and confronted the stallholder who denied all knowledge, but within a few minutes had removed the goods back into his van. He knew he was in the wrong. Someone like this would be unlikely to willingly come forward with information in the Wynarka case, IMO.
If I were a detective, I would be looking at the care label in the SIDE SEAM of the garments as this is where the unique manufacturer code is situated. That, IMO, is more telling if the centre back label is not recognised.
Sorry to ramble on. I hope the above makes sense.