It sees a bug THERE. It knows when it spits, the spit goes in THAT direction. That's all that's necessary. The fact that THERE and THAT are not really in the direction the fish sees is immaterial.
Correct. And it's the same for humans.
The image that is projected on the retina by the lens of your eye is upside down and backwards. You can prove this by closing your eye, pressing gently on the eyeball at the edges of your eye sockets, and observing where the dark spot in your vision appears. The wiring in your optic nerves and brain corrects for this inversion without your conscious effort.
Likewise, the wiring of the eyes and brain in the archer fish has evolved in such a way that it automatically compensates for refraction. There is no mystery here, and I find this a pathetically weak argument in favor of young-Earth creationism.
-ccm