Would you keep waiting in this situation?

The key word here is "can". This sometimes happens, but in very few dogs. Now, they just say that raisins are bad for all dogs just to be safe. If he Had acute renal failure, he would be very sick right now. Since he seems fine after a week or so, I would say everything is fine, and not to worry. Dogs eat things all the time. My dogs actually get raisins for treats sometimes (since they were puppies), and they are 6 and 7 now; perfectly healthy. If you are really worried, try to use an online translator and go to the vet. Translate "My puppy ate raisins. Can you tell me if he is sick" in Korean. I would also say this to the vet in korean "I don't know korean, I just translated these sentences". This way, maybe he will shake his head yes or no on if your dog is sick. Or, you can hire a translator. I would say he is fine, but go to the vet if you want. I don't think this will happen, but as you said...you don't wanna lose the little guy!