I suppose that, had Conan Doyle been aware of quantum mechanics, Sherlock Holmes would have spent a portion of every case entertaining the notion that quantum phenomena caused the universe to spontaneously arrange the crime scene.
Holmes was famously ignorant of any knowledge that didn’t help him solve crimes. In his own words:
“You see,” he explained, “I consider that a man’s brain originally is like a little empty attic, and you have to stock it with such furniture as you choose. A fool takes in all the lumber of every sort that he comes across, so that the knowledge which might be useful to him gets crowded out, or at best is jumbled up with a lot of other things so that he has a difficulty in laying his hands upon it. Now the skillful workman is very careful indeed as to what he takes into his brain-attic. He will have nothing but the tools which may help him in doing his work, but of these he has a large assortment, and all in the most perfect order. It is a mistake to think that that little room has elastic walls and can distend to any extent. Depend upon it there comes a time when for every addition of knowledge you forget something that you knew before. It is of the highest importance, therefore, not to have useless facts elbowing out the useful ones.”
“But the Solar System!” I protested.
“What the deuce is it to me?” he interrupted impatiently; “you say that we go round the sun. If we went round the moon it would not make a pennyworth of difference to me or to my work.
Given this, I’m not sure Holmes would bother with a quantum viewpoint of the world, since the theory wouldn’t help him solve crimes.
My comment was a bit tongue-in-cheek, but if we're going to push our glasses up and engage in some good old well-actuallying, I'll note that Conan Doyle appears to have retconned Holmes' self-professed ignorance later on, as he calls on knowledge of astronomy to solve a case at least once: https://adsabs.harvard.edu/full/1993JBAA..103...30S
Perhaps the leading sentence by parent was not a true speculation, just an elaborate setup to the slightly altered quote as the punchline. In an alternate universe, if Conan Doyle took more interest in the digestive system of the human body, Sherlock Holmes would've explained everything with gut feelings instead of making extended retreats to his Mind Palace.
If you don't know it already, you might be interested in 'Dirk Gently's Holistic Detective Agency' by Douglas Adams and/or the funnier second part 'The Long Dark Tea-Time of the Soul'.
"It's elementary particles, my dear Watson."