This could be a real problem, or not much of one at all. It all depends on the size of the holes that Dean drilled in the body for the neck attachment screws. If they were drilled to be the exact same size as the pilot holes in the neck, then you have a problem, because the screw threads will bite into the body just as much as the neck. This is what
@gasket illustrated in post #20.
However, if the holes in the body were drilled larger than the pilot holes were drilled for the neck, the screw threads may just be catching a bit in the body wood, but not as much as the neck (depending on the diameter of the holes). If this is the case, you may be able to do what
@jtcnj suggested in post #38. In fact, once you get the other screws out (assuming they don't break, too!), you may be able to get the neck off by just pulling on it as you wiggle it a little bit. But, pay attention that you don't splinter the wood in the process.
Again, it all comes down to how deeply the screw threads bite into the body material. I would assume they used a larger drill for the body to avoid the situation
@gasket mentioned, whereby the screw could actually be tight to the point where you can no longer turn it, but the neck isn't being pulled tightly to the body.