Crazy Jerome
First Post
Yeah, that's fine.
What I am trying to wrap my head around is the chimes of, effectively, "Of course a good GM will not let someone move like that!" (despite the rules allowing it), when said movement is hardly the most difficult narrative gap to fill (or fantastic "mundane" occurance happening).
If I was running 4e, it would be because I didn't care if the rules simulated the fictional reality (i.e., substituting narrative to fill the gaps as you suggest), or because the fictional reality was of the type that the rules simulated (like Mallus' extremely clever concept for a 4e campaign milieu).
The point is, I don't imagine that I'd even raise an eyebrow at the jump. Certainly not in comparison to everything else.
So, what am I missing?
You are missing that DM advice wimp out I mentioned. The DM advice is all heavily geared towards going with the latter option. You say yes and let the players go with the fictional reality produced by the rules.
It's not even really bad advice, giving the dedicated effort in the text to make the game as beginner friendly as possible, giving the complexity of the rules. It is also not bad advice giving the historical tendency of new DMs to get a little carried away and strident with, "No." And it never hurts for even experienced DMs to see if they can't find more ways to say, "Yes."
But there are a lot of "exceptions" in the DMG which are unwritten in the DM advice but implied in the nature of the rules. This heavily favors not confusing beginners over showing the options for growth as a DM. A good, experienced DM is, of course, going to look around, realize that this particular table will have a more supple game with filling in the narrative, and go with that. If his players screech when he says, "No" or even "only if you tell me how in a way that satisfies most of us here"--then he will have to bring them along.
Warning--Gross Generalization: This is the Robin Laws versus Luke Crane dichomoty. Laws is all improvisational "Say Yes" all the time, make them succeed, etc. Be nice to your players and thus help them tell the story they imagine. (Read the rules for Faery Tale Deluxe some time.) Crane is rat bastard DM, where "Say Yes" is give on thing A that doesn't matter so that you can get to nasty thing B all the faster, and make them sweat. Instead of saying, "No," you say, "Only if you tell me how to screw over your character if you fail". Be really mean and pushy to your players and thus help them tell the story they imagine.

4E is a game more supple in the hands of someone who leans towards Crane, with advice that leans heavily towards Laws. But you can't do both at the same time.