I've had two batches not carb on me, but I stirred my boiled priming sugar in, so sugar dispersion was not the case. My problem was yeast. Anyhow, what I am getting at is if you had issues with sugar dispersion and yeast dying off, you can hydrate some EC1118 (it's a dollar!) and add 1/2 tsp of sugar to each bottle. Recap and you're done.
If you're scared the yeast died and you now have too much residual sugar leftover, don't add more sugar when you add the EC1118. Bad news is if you have a lot of sugars left over, the new yeast may have too much food to eat and blow up more bottles, but that's probably not going to be the case.