He arrived in South Vietnam in February 1969 and served as a Stretcher Bearer in C Company.
On the night of 4 July 1969, Private Herbert was with 7 Platoon occupying an ambush position. Enemy forces were known to be in the area and contact was expected. An enemy mine was exploded in the darkness causing 12 casualties, many of them very serious. Soon afterwards a second mine was exploded wounding all but four of the remaining members of the platoon.
Private Herbert was severely wounded himself causing the immediate loss of one eye. Despite the fact that he could no longer adequately see and was in great pain, Private Herbert continued to move and feel his way around to give treatment and comfort to all his wounded comrades. By his own efforts he undoubtedly saved several lives while further risking his own.
When additional medical assistance could be flown into the area some time later, the relief medical non commissioned officer reported that Private Herbert had completely organised the casualties and professionally carried out all the field treatment of the 18 wounded that could have been done.
By his remarkable display of courage Private Herbert gained the admiration not only of those he treated but of all ranks of his Battalion. His actions reflect great credit on himself and The Royal Australian Regiment.