You have to put the information into the context of the time
Cook came from a country which even in that time had a visible population, England at that time was obviously inhabited with many thousands of years occupation also visible , he estimated that the Sydney population was about 1500 people
He did not travel far from the coast but he knew at by that time that Australia was very large and the number of people that he encounted obviously did not equate with the country being an occupied continent
He certainly did not go a look for odd arrangements of rocks to see some form of fenced barriers.
So regardless of what you would like to prove he did not make a mistake in his assumption, if in today's scientific evaluation of current evidence the decision can be proved incorrect then you can look at almost any decision made 200 years ago and find that it could have been wrong as well which is not an excuse to re-write the actual history
To try and re-write history and try and make amends and excuses for a decision that Cook made is plain and simply stupid
As to the current population it does not reflect truth either because anyone with even a small amount of Aboriginal or Torres Straight Islander blood from a far distant ancestor or a person who has been adopted by a tribe can be called a Indigenous Aboriginal as far as the census is concerned
Do the research and try and discover as much as possible about the life of this land, also try and discover more about the people who are not allowed to be discussed because it may upset the current Aboriginal population IE they ones they displaced
But for heavens sake don't re-write any more history just tell the facts and the truth which has been sadly lacking in this modern age
