The bodies of Robert and the sapper were eventually transported to the Kiwi cemetery at El Alamein, where they rest with the 2998 other New Zealanders killed in the desert battles between July and November 1942.
"[Robert] was a dispatch rider," recalls Wattie. "He'd just done his rounds and come back and a mortar collected him and a sapper. They couldn't separate the bodies."
Wattie's fellow Alamein veteran Eric Wilson, a gunner in the first ammunition company, 24th battalion, visited the double grave when 23 Kiwi veterans returned to El Alamein last year. He took a photo for Wattie, who was supposed to be on that trip but withdrew after being diagnosed with cancer. The disease is in the bone marrow of his spine. It can't be treated. He doesn't know how long he has left. He hasn't asked.
"Someone will tell me," he says quietly.
Both 94, Wattie and Eric are members of an ever-shrinking group.
"All of my cobbers are gone," says Eric. "I am the only one left out of my platoon ... I wasn't good enough for the Lord to call."
That last sentence is delivered with perfect comedic timing. Despite the advancing years, Eric and Wattie remain keenly alert.
Eric produces a photo of a monument to the fallen at El Alamein. He points to the name of Alby Storey, the "spare driver" of his truck.
Storey was killed when the truck was mistakenly attacked by the RAF at Gambut, near Tobruk. The truck didn't have an RAF insignia on the roof, so an officer was supposed to wave a flag to identify it.
"We were taking shortcuts across the aerodrome," recalls Eric. "Unbeknown to us it had just been taken. [The officer] forgot to wave the flag, he was in a slit trench, so we got the works. I'd always told Alby - first time in action for him - to lie down underneath the motor because that's what we did in Greece. He did that and he got shrapnel right through the engine block. He died in the ambulance."
The scars of El Alamein run deep. Eric and Wattie have neither forgotten nor forgiven.
"I can't speak for Eric but I hate 'em," Wattie says of Germans. He doesn't buy the line that ordinary Germans were distinct from Nazis. The soldiers at the front must have received plenty of support from the people at home, he reasons - "particularly when they were winning cheap victories, over-running countries, destroying nations and carrying out shocking acts, even on their own people".
"So to me the German was an Adolf, he was a bloody Nazi. It makes it easier to kill them, anyhow.
"Freyberg had the right idea. He told us that we had to crush the Germans, drive them back inside their own border and crush them. You notice Germany and Japan, since the war went to their countries, they haven't made any hostile movements in 70-odd years."
Wattie and Eric share a strong admiration for Freyberg, the highly decorated English-born, New Zealand-raised general nicknamed Tiny, who famously "led from the front".
Wattie even wrote a book about him - The Salamander's Brood - a portrait of Freyberg through a soldier's eyes.
But over a beer at the Howick RSA, the pair are scathing in their assessment of the British officer class, who came across as aloof, and had a callous disregard for the soldiers under their command.
"[The British soldiers] were so brave it was almost silly - you would almost think that they were expected to die," says Wattie.
Thousands did. Exact casualty figures are unknown, but estimates put the total of killed and injured on both sides of the desert war at just under 75,000, with Italy suffering by far the greatest losses. The New Zealand Division's losses were 2989 dead, 7000 wounded and 4041 captured.
The Allied victory at El Alamein is regarded as a turning point of the war.
"Now this is not the end. It is not even the beginning of the end, but it is, perhaps, the end of the beginning," said Winston Churchill. After the war, he wrote: "Before Alamein we never had a victory. After Alamein, we never had a defeat."
On screen
Broadcaster Cameron Bennett travelled to El Alamein with a group of 23 New Zealand veterans last May to mark the 70th anniversary of the battles. His documentary, El Alamein: Line in the Sand, screens for the first time on Anzac Day on Maori Television at 7am.
