An account of the incident in Waugh's military file states that at this point, the soldiers, from the 2nd Anzac Cycle Battalion, talked among themselves about the figure on horseback. Ominously, they formed the view that he was a German spy.
Around 11.20pm, for the third time that evening, Waugh appeared at the checkpoint and was met with a challenge from Private Arthur Connolly, a young Australian soldier. Connolly, armed with a loaded rifle, asked Waugh to provide proof of identity.
The 38-year-old Scot, who could be "sharp and sarcastic" according to his personal file, replied: "I am a New Zealand captain" and demanded to see someone in command.
Connolly held the bridle of Waugh's horse, while another soldier went in search of an officer.
At this point, according to Waugh's file, the testy rider struck Connolly and took off at a gallop. The NZ Veterinary Corps officer was urged three times to stop but refused.
The soldier fired at the receding figure, wounding Waugh in his lung. Soldiers collected the injured Waugh and took him for treatment. He died the following morning.
A Court of Inquiry ordered by the NZ Divisional Commander Sir Andrew Russell found that when Connolly fired the fatal shot he believed Waugh was a spy. The death was recorded as accidental.
The irascible Waugh was not the only serving vet to die in unusual circumstances. Captain Jacob Hope Primmer, one of 26 vets on active service caring for the thousands of horses New Zealand sent to war, died on the Western Front in June 1917, killed during a lightning strike.
A report published in the Northern Advocate said Primmer was sheltering with artillery soldiers in a cookhouse during a violent storm. Lightning hit their hut. Primmer was killed instantly.
Gunner W.J. Wilson wrote about the tragedy in a letter, saying "his case was rendered particularly sad by the fact that his wife was in Paris expecting him to go and see her".
It seemed strange, Wilson observed, "that when the enemy's effort to kill had failed, Nature should take a hand in the business, with such tragic results".
To read the first 81 stories in this series go here.