According to Henry's account, he took aim but had a heart not to kill a wounded German soldier. “If I only had known what he would turn out to be. When I saw all the people, women and children he had killed and wounded, I was sorry to God to let him go.” 
God (if I dare to speculate on that subject) must have seen the scene in a different light. He knew who the wounded German soldier would become, for there are no limits to God’s knowledge. But God didn’t send an angel to Henry (pull the trigger, good lad) nor didn't he kill the Führer-to-be in a million of other ways, as he could, but he left the choice to the man, Henry Tandey.
God gave the choice not only to Henry Tandey. He gives a choice to everyone. Including the wounded German soldier, who yet will have to recover and to make his own choices, which a few years later will bring him to Nazism. (Hitler will join Deutche Arbeiterpartei or DAP in Munich, in July 1919 as its 55th member.). And even after that, after joining DAP, Hitler still will have to make numerous choices, which will make him one of the most criminal characters in World history.
Would world history be different if Henry Tandey had killed the wounded man? Likely so. But history would be different as well if Herr Hitler would devote himself to painting and instead of returning to Munich, say, move to live in Southern Italy, or Tahiti for that matter, or if he would fall in love, marry, have children, leave Reichswehr. Who knows? One may say that God moves in mysterious ways. No question about it, but a man makes his moves in the light of God or away from it, in shadow.
 National Geographic 100 Shocking Events. Disasters, Scandals, and Adventures That Made History, 86. Hitler's Regrettable Ninth Life, National Geographic Society, Washington, DC, 2017, p. 108.
 Bill Yenne, Hitler's Master of the Dark Arts. Himmler's Black Knights and the Occult Origins of the SS, Zenith Press, Minneapolis, MN, 2010, p.45.
Christian Faith and Prayers; Literature, Art, Music, Culture and Nature
I am having some second thoughts about this historical anecdote. It is all just mindboggling. The story of Henry Tandey is somewhat anti-symmetrical to the story of Gavrilo Princip (see REFLECTIONS ON JUNE 28", 1914.) A bullet fired by Gavrilo Princip lead to demise of millions of people, while a bullet fired from Henry Tandey rifle could save millions of lives (including 16 million German lives). Tragically, both cases brought the worse outcomes possible. Of course, Henry Tandey didn't have to shoot Hitler, he could simply bayonet him. And that would do.