"If Pte Manning had been removed at the time of the email the alleged assault [on Showman] would not have happened," defence lawyer David Coombs said.
Captain Steven Lim, one of the senior officers in the unit, earlier admitted that he was not told the details of two other incidents in December 2009, where Pte Manning allegedly made emotional outbursts and at one point had to be restrained because other soldiers thought he was trying to grab a weapon.
Cpt Lim told the hearing that despite specific regulations prohibiting it, soldiers would often play games and listen to music on computers that had access to the Army's secret networks, and from which Pte Manning is alleged to have stolen military and diplomatic files using blank CDs.