Cyril Falls, a British official historian, criticised the British army for the failings it showed during the German withdrawal to the Hindenburg Line, writing that the divisions were "bewildered and helpless", until they gained experience in the new form of warfare. The commander of the 8th Division, Major-General William Heneker wrote on 2 April, that it had taken three weeks for his division to become proficient in open-warfare techniques. In April 1917, an analysis by II Corps had found that patrols coming under fire had stopped to report, ground of tactical importance had been ignored by patrols that had returned to British lines, forfeiting opportunities to force German withdrawals and artillery had been reluctant to push forward. Liaison between divisional engineers and artillery had been poor, advanced guards had not known the importance of reporting on the condition of roads, ground and the accuracy of maps; the cavalry element of advanced guards was also criticised for hesitancy although in contrast, Charles Bean, the Australian official historian, concluded that the advanced troops of I Anzac Corps had been sent out on a limb.