He was evacuated and did not rejoin his regiment until 1 July. When Brigadier General Chauvel took over the New Zealand and Australian Division on 19 September, Cox became acting commander of the 1st Light Horse Brigade.
Initially evacuated, he reentered his regiment on 1 July. Upon Brigadier General Chauvel's taking over command of the New Zealand and Australian Division starting from 19 September, Cox served as the acting commander of the 1st Light Horse Brigade.