Wait, I thought the wedge was already out of the equation, based on post # 4. But now it's sounding more like a garden-variety broken stem. If the wedge has NOT been removed (well, "released" would be more accurate, I suppose), and is still engaged with the bolt, AND the stem proper is broken in two pieces below what we can see, you'll experience just what you're describing. The bottom bit of the broken stem will "affiliate" with the wedge and not want to turn or come out, even while you're lifting and wrestling with the rest of the stem. It's happened to me, but only with aluminum stems, never with steel. That said, never say never....

Try this - Pull upward gently on the stem, and continue turning the bolt counter-clockwise. That upward pressure should (well, might) hold the broken bit / wedge from rotating, and you might eventually get the bolt to unthread entirely from the wedge, releasing it, and the busted bit of stem, to fall into the steerer. Then the main part of the stem should just pull out, and you should be able to flip the bike over and the rest will drop out.

If that's not it, you might also shed some light on your situation by looking from underneath; you may even want to remove the brake bolt, just for a better visual sense of what's going on.