The leader's choice of October for setting out was not a good one but information on weather patterns to guide him was meagre in the 1840s. The heavy rains did not lead directly to the failure of the project although they, coupled with an unwise choice of diverse stock, did impede the progress of the party, and the heavy labour associated with lost and bogged stock probably contributed to a lowering of the men's resistance to disease.

Leichhardt's decisions on the diversity of stock taken were influenced by the unofficial nature of the project, his limited financial resources, and his recognition of the very long period that the expedition would be in the field. He failed to take sufficient medicines, but even if more were taken, it is likely they would have been ineffective. There was a breakdown in personal relations between some (but not all) members of the party and their leader, to which Leichhardt contributed because of his unusual ideas. Nevertheless this occured largely in the sick camps and on the return home and the expedition would have pressed ahead if it had not been for the recurring fever which Leichhardt had no means to control. This disease was transmitted by mosquito and was probably dengue fever. The sickness led, not only to a physical unability of the party to continue, but to the dispersal of the stock on which the expedition relied for food and transport.

On the available evidence then, Leichhardt can largely be absolved from charges that his incompetence and lack of leadership ability were responsible for the failure of this, his first attempt to reach the Swan River.