I have found that this characteristic is not consistent as it can also be found on some specimens of L.o.olivaceus found in the Kununarra area of W.A, and therefore should not be reliably used to identify L.o.barroni.
Although L.o.barranoi was described by Smith in 1981 on taxonomic scalation differences, I believe that it still remains unclear as to whether or not L.o.olivaceus is really absent entirely from the Pilbara region. I have personally looked over several specimens from the DeGrey area of the Pilbara and relying on these taxonomic differences to quantify what is widely deemed to be the accepted differentials of the two, can confirm that the Degrey populations key out as being L.o.olivaceus in both mid-body and occasionally on ventral scale counts. It is interesting though that the small triangular scale between the internasals and rostral scale was either absent in some specimens or extremely reduced in size and hardly visible in others.
A paper written by Lesley H Rawlings, David Barker, and Dr Stephen C. Donnellan in 2004 on mitochondrial DNA, has shown that there are indeed DNA differences between the Kimberly and Pilbara populations to perhaps further validate the acceptance of two species. Unfortunately the Pilbara specimen's used for DNA examination were only taken from specimens obtained from the Pannawonica area. The DNA of the Pilbara coastal population which are found a further DNA 540 km North West of Pannawonica were never looked at presumably due to the lack of available specimens.
As the DeGrey population is so far away in distance from Pannawonica, and in reality, is a similar distance from the northern olivaceus population found near Broome, it is my opinion that further mitochondrial DNA work may confirm a form that is an intermediate of the two or at the very least will prove that Smiths taxonomic description is flawed and needs revising. I believe there is an unlikely chance of gene flow between both northern and south eastern areas to the Ord Ranges because of its isolation.
In my opinion the only possible chance of limited gene flow from the Eastern Pilbara Olives and the Ord range population would be via the East Strelly or DeGrey river tributaries during the wet season. As the western areas of these rivers are void of rocky habitat and travel through a vast expanse of desert like area and are mostly dry for much of the year, gene flow may not be likely.
The Pilbara Olive has an extremely docile demeanor and besides the logistics of housing such a large python, make excellent captives. In the wild at both day and at night time, I have commonly found Pilbara olives submerged in water holes with just their nostrils protruding the water surface and have observed specimens fully submerged actively swimming around seemingly without effort almost as if they were eels.
It was previously thought that the Pilbara olive was a relatively rare python but this is definitely not the case at all and I would consider them in there remote habitats as being common. Dr David Pearson a scientific officer from the Department of Environment and Conservation has being radio tracking work with this species for a number of years now and I am told that his recommendation is that they should be removed from the endangered species list.