Meaning no disrespect to Charles Harper, but I don't know how he came to be regarded as a casualty of the First World War.
He was indeed the cook on the merchant ship Dunsyre, and he did die at sea on May 15, 1914. His death was a suicide following a day or two of fever and headache. He told the captain he felt well enough to go back to work, but then in the night, he disappeared from the ship and the captain felt there was only one conclusion to draw.
Charles left a note on his pillow, leaving very little room for doubt about his death.
He was an American, and the captain thought he might have been using an assumed name. I tend to agree, though I cannot prove for certain what his true identity was. Best guess is that he was a son of Mr S A Smith of Fort Dodge, Iowa.
I have written more about this on my website. I have done more research than what is there. I was trying hard to find a justification for Charles being entered in the Book of Remembrance, but so far, I have found none and I have run out of even wildly plausible explanations. I put it down to innocent bureaucratic error.
My website is jillbrowne.ca and the story about Charles is here: http://www.jillbrowne.ca/2014/07/29/who-was-the-first-canadian-to-die-in-the-first-world-war-is-there-a-mistake-in-the-books-of-remembrance/
I should add that I am new to this site. If I have accidentally said anything incorrect about it, please do correct me. I appreciate the opportunity to share this research. My objective is simply to add to the historical record.