The blacks now drew back a little, and the men seized the opportunity to warn the bullock-drivers, whom they found occupied in lifting a bullock that had fallen into a bog.

Their arrival probably saved their lives, as the bullock drivers were unarmed.
No further attack took place, but the strictest watch had to be kept until the party was ready to begin the return journey or to beat a retreat as the natives regarded it.

They reached Fort Bourke without further molestation, the aborigines being content with having driven away the whites, who retraced their steps from Fort Bourke to Bathurst.
The geographical knowledge gained on this journey consisted mainly in the confirmation of tentative theories -- the identity of the Karaula with the Darling, and the uninterrupted course of the latter river southwards, as Major Mitchell himself had to confess, into the Murray.

Furthermore it seemed now satisfactorily settled that all the inland rivers as yet discovered found the same common embouchure.

Mitchell's experience too proved that the pastoral country through which the Darling ran was by no means unfit for habitation, nor was the river a salt one; true some of his men had noticed that the water was brackish in places, but this brackishness, it was seen, had a purely local origin.
Mitchell was a keen observer of the habits and customs of the aborigines.
He was remarkably quick at detecting tribal differences and distinctions, and his records of his intercourse with them -- which occupies so much of his journals -- were most interesting then, when little had been written on the subject; and are even more valuable now, as a first-hand account by an intelligent man and a practised observer of the appearance of the natives at the time of earliest contact with the white man.
7.4.AUSTRALIA FELIX.
One would have thought that the fact of the union of the Darling and the Murray was now sufficiently well-established; but the official mind deemed otherwise.