New Zealand medics on Crete

This is my first attempt to find information about my father's experience on Crete in a NZ Field Hospital. My father, from Australia's 2/3rd Field Regiment, was injured (shot in the arm), and was treated in a New Zealand field hospital near the Maleme airfield. The New Zealand doctor in charge was desperate as he had run out of medical supplies and in particular had no morphine for the injured men (including German paratroopers) so on the 27th May 1941 my father, whose injury was not so serious, walked to Agia Marina (between Maleme and Hania) to see if he could get some supplies. I'm not sure if there was a hospital there or just a base for his regiment. When he got there he discovered the allies, under assault from the Germans, would be withdrawing that night. My father was horrified to learn that all the men in the field hospital were to be abandoned.

He managed to get some morphine to take back to the field hospital. However, my father was very angry that all these injured men (about 60 of them) were to be sacrificed and on the way back he took a truck from an olive grove, found another soldier to drive it (he couldn't drive it himself because of his injured arm) and while under heavy bombardment from the Germans he went back to the hospital and in several trips rescued all of the men including the Germans. I don't actually know what happened to the Germans after my father rescued them all. I presume they were taken prisoner. My father then walked south to Sparkia from where his regiment was evacuated to Palestine.
I know it's a really remote chance, but it would be wonderful if any of those men he rescued on that truck were still alive. My father died at the age of 91 nearly 3 years ago but before he died a book (as yet unpublished) was written about his life. He later became the founding Commanding Officer of Australia's elite SAS Regiment. His name was Bill Brathwaite. Can anyone assist me with information or tell me where I might go to see what I can find. I live in Sydney.