My peppers ( along with 95% of the garden) were decimated by snails/slugs this year. The snails outright killed all the tomato, squashes, lettuces, cukes, melon seedlings by eating the starter leaves. I'd plant a sprouted seedling and the next day would come out to a leaf-less stalk that never produced another leaf! The peppers they harmed and made them stunted. They chewed around the stem in a circle. So the stem is half the circumference at ground level as it is at the 3 inch level. They also chewed holes in the leaves. I never saw the snails and slugs till I went out after a rain and it was almost dark. They are nocturnal, as far as I can tell. I tried hand picking them but got discouraged when I picked up 200+ and went back to the 1st row in the garden and there were just as many crawling ones again! I bought Natria at a Lowes store and it's a slug bait that is organic- approved. It's iron phosphate and the slugs eat it and overdose and pass away. It works extremely well, if that turns out to be your culprit.

Well you can still see what I'm concerned with in the picture above, the very light green areas. It almost feels like the top "layer" of the leaf is gone. The light green areas are stiffer than the rest of the leaf, and towards the edges it was starting to really dry out and harden, yet wasn't turning brown. I'll take another picture and try and get more detail, however my camera isn't the best as close-up macro shots.

It would be good if you could post a picture of both sides of the leaves. While there are some recognised diseases of Eucalyptus (both sides of the Big Pond) it seems curious to have your plant come complete with fungus out of a nursery in the first place (you'd expect great plant hygiene) or, if locally air-borne, to be so fast to attack. We have a variety of sucking and leaf-eating insects in Australia that can cause damage depending on species and location - it might be hard to find an "un-touched" mature leaf in natural growing conditions. There are some forms of rust too, but you could tell the difference yourself. It could simply be a bruising reaction to damage in transit? anyway a picture or two would be useful, you can post here or in the Aussie "Gallery"

Could be flea beetle damage. They are pretty small (1-2mm) mostly dark colored bugs that hop around, and will hide out in the soil until conditions are right. Unless the populations are high, they really don't do serious damage to plants. Your peppers don't look that bad. They overwinter in soil and become active when it gets warm. If your pots are inside, that'll do it. Using unsterilized soil in pots is a good way to get them. You should look carefully at the pots and stir the soil gently to see if you can rouse any. If you don't want to use pesticides, sticky traps might help.