In which we attempt to slay the Quantum Ogre

Or Heisenberg's Ogre.  Or Shoedinger's Ogre.  Whatever the kids are calling it these days. 

By whatever name, it seems to be an insidious beast – like Pellinore's questing beast or Antigonus' bear. And I'm unsure how much attention in should be given. Definitions seem to vary slightly. Giving the players a choice (two doors) but determining that the ogre will be behind whichever door they chose, seems to be the dominant definition. But how is this different from determining random/wandering encounters in advance?

I know that the party will have three random encounters as they move through the Edward Wood. I use a nice sufficiently random table and determine that these encounters will be a patch of razor vine, and abandoned farmstead, and an ogre. I have no idea what path they will take through the wood. I don't know how fast they'll be moving or what other silliness they might engage in. They might zip through the wood at breakneck speed, dispatch the razor vine with alacrity, ignore the abandoned farm completely and zip right by, encountering the ogre being relatively fresh as they exit the wood.

Or they might take their time dealing with the razor vine, analyzing possible solutions and discussing alternative solutions. They might even kill some time “beating the bushes” to see if other travelers might have dropped a coin or two. They might decide to rest and recuperate in the abandoned farm house searching it high and low for signs of habitation, usable detritus, or lingering beasties. I'll likely even GIVE them a swarm of rats or something, just to reward their inquisitiveness. And then, after 3-5 days of traipsing through the wood, they'll encounter an ogre.

Or perhaps the ogre will manifest while they're trying to solve the implacable riddle of the razor vine, or as they investigate the architectural integrity of the abandoned farrowing shed.

Am I therefore an evil, bad GM for denying them a choice? Isn't ANYTHING I place in their path a quantum ogre?

Here's how it currently works at my table. Party is wandering listlessly through the untracked wilderness. Roughly every two miles there WILL be an encounter. I use this nifty little random encounter generator. It gives me five encounters from which to chose. My choice is predicated on what they've been doing and what the options presented are. Some just don't fit the story. Some are tougher than they need. Just did a check: scouts, herd of wild boar, tribal war party, band of thieves, and a werebear. The wild boar present a nice opportunity to forage. The werebear just doesn't fit right now. Neither do the thieves (unless I wanna go Robin Hood on their asses with a bad Kevin Costner accent.) The scouts could be a nice tie in to a local band of H/G's, as could the tribal war party.

So the ranger either picks up the trail of the boar, or they spot them 90' away. Get a first shot. Roll initiative. Field dress the result. Move on. Virtually NO choice the players made resulted in the boar being there. Quantum boar? I've also started using a tension pool. When we spill the bowl and a result occurs, I determine what the result is. Quantum tension?

I guess my question is that SINCE the DM is the eyes, ears and nose but not the throat. NEVER the throat) of the party AND SINCE nothing in the world exists unless and until the DM shines the flashlight on it, isn't there in fact a quantum ogre lurking just beyond every next perception check? The world is wholly made up of quantum ogres!