[3] On 19 June 1940, during World War II, Lamb enlisted in the Second Australian Imperial Force, and was posted to the 2/2nd Pioneer Battalion.

In early 1942, Lamb's battalion and several other units were returning to Australia on board the SS Orcades, but once the ship landed at Batavia, they were ordered to defend Java against Japanese forces which had begun to move through the Dutch East Indies.

Lamb was still listed as missing in action at time of the Victorian state election on 12 June 1943, however he was re-elected unopposed to the seat of Lowan.

[8] On 7 December 1943, Lamb died at the Japanese work camp 131 Kilo in Thailand, suffering from malaria, dysentery and malnutrition.

[11] Confirmation of Lamb's death triggered a by-election in the seat of Lowan, with the writ issued on 28 September 1944, and polling on 4 November.

[13] His son, Tony Lamb, would also go into politics, representing the federal seats of La Trobe (1972–1975) and Streeton (1984–1990) for the Australian Labor Party.