It's late and I may be having a big brain fart, but I don't see the "A implies B" meaning "not A implies not B". Even the rain example: it can be cloudy and not raining, right? I would see something like "if something is a X, then it is Y" equivalent to "if something is not Y, then it is not a X". Now you can replace X with raven and Y with black and that's your raven paradox. Am I missing something?
Anyways, thanks for the brain teaser.