Ovinomancer
No flips for you!
A random roll seems appropriate. The situation is somewhat strained already, though, in that the GM choosing the ogre via fiat does seem to be an intentional nullification of the player's choice but more of a 'crap, Imma make a call' that unintentionally does this. There's no intent to deceive, just a choice between rather lackluster and non-great options for how to fix a mistake. I'd likely be open about this and tell the players that there's a mistake in the adventure I've just noticed that doesn't correctly key these rooms so roll me a die -- even it's the first listed, odd it's the second.The purpose of my question and hypothetical was to increase my understanding of how @Maxperson defines the term "railroad" in practice. Based on what I understand of their views on railroading so far, I don't think their answer to my question is going to be variable based on campaign style. Accordingly, I don't think the question required more information to be useful for its intended purpose.
That said, I'm happy to discuss my question in the more general context in which you've framed it. I entirely agree that if one is playing at a table where there is an expectation that room contents be fixed in advance, it is problematic to either not have the room contents fixed in advance (as my question supposed) or to re-arrange room contents on the fly, as the GM would be violating the social contract in either case.
The focus of my question, however, is on how a GM might fix the problem of incomplete notes that don't unambiguously assign contents to the two rooms. For example, a module might list:
Area 19. Two identical 15x15 rooms originally intended for storage. One contains assorted bags, chest, barrels, and shelves full of long-decayed perishables. The other has been cleaned out and repurposed as a bunkroom for an Ogre, who is sitting at a small table eating a meal.
Suppose the DM doesn't discover that the module fails to indicate which room is which until after the PCs have declared that they open the left-hand door. My interest is in learning from those with more-absolute definitions of railroading what techniques can be used at this point (if any) to avoid the GM railroading the players as they try to fix the oversight in the prep.
And for specificity, my interest in asking the question at all is because I personally view GM motivation as important to determining whether or not something is railroading, and I want to better understand the position of those who think that GM motivation is not relevant to what is and is not railroading.
Because, at the end of the day, this is a blind choice, which isn't particularly enabling of agency or authority even though dungeons are full of such choices unless the GM makes a concerted effort to foreshadow.