ORIGINAL: majortom-RCU
Dirtybird's 'unequal shrinkage' diagnosis is interesting, the implication being the bottom & top skins had different moisture content before they were applied. I suppose that's possible, but it seems to me if that were true the warpage after they equalized to the same moisture content would be an arc of uniform radius, or perhaps a progressive radius because of the taper of the wings. However, what I see in the last photo looks more like a long straight stretch, then an angling off by a degree or so, then a shorter straight stretch out to the tip. So I find the 'crooked table' explanation, or just a sloppy job, more likely.
That sure would be a crooked table.
ORIGINAL: majortom-RCU
If I were prepared to sacrifice the warped wing to science, I would razor saw just the depth of the balsa sheet chord-wise at the high point of the angle, then see how light a touch of compression would straighten the angle out. Maybe it would take a few parallel cuts, but I would be looking for a straightening of the angle with not a lot of force at the wingtip. When you have the right cuts in the right places, then glue the balsa sheet back together. Fortunately the warp looks to be well out toward the wingtip, where the flight stresses would be much less than if it were closer to the root. If this worked, I'd be very pleased with myself, and thank Dick for the good tip.
The strength of the wing is provided by the balsa sheet. Doing this will result in a straight but weak wing