D&D's worlds are based on exceptions. Where one draws the line is subjective as what one can accept. Some people can accept child-sized adventurers, others cannot. Some people can accept Dwarves being able to swim, others cannot. Some people can accept giant-sized ants, bees, and other creatures existing in the game, others cannot. Some people can accept that something as large as a dragon can fly about at great speeds without the necessary wingspan, others cannot.
I could go on, but the fact is, even if we assume "D&D worlds are like Earth, save for exceptions", there's a lot of exceptions, many grandfathered in since the earliest days of the game, and not all are noted as being such.
To argue that "this is unrealistic but this other thing is acceptable" when both exist in the same game is not going to be very persuasive. Some will want citation to know precisely what is simply the way things are meant to be, and what is a mistake- but games are notoriously inconsistent with providing citations. Sometimes a Wizard (God) did it is all you get.
Now this thread was intended to talk about when the DM gets the science wrong, not the game designers! And of course, it goes without saying that the DM (or the designer) is only wrong if they make the statement that "we follow the science".
D&D is not a reality simulator. Gary Gygax makes a point of this back in the AD&D 1e DMG and I've never read any D&D book that tells me it's meant to simulate reality- quite the opposite, in fact. Any relationship to real-world physics in a D&D world is coincidental, as the physics involved with magic ships sailing between crystal spheres through the phlogiston or disc-shaped worlds (the tenth planet in Oerth's star system for example) exist because we're told that they do- nobody is claiming that Greyspace is intended to simulate our universe's physics, so the fact that The Wink exists doesn't necessarily make it an anomaly or mistake- only by claiming it isn't an anomaly or mistake would make it one.