There is no way to tell if it was a fluke or if there are underlying issues - if she has another failed litter it could be due to something wrong with the doe, if the next one is kindled without a hitch I would say it was a fluke... I had two does (I don't know their background, but I wonder if they were sisters) that had issues with large, dead kits and each litter was worse than the last. They also were gaining weight despite the same food amounts as all the others (total roly-polies). I found each one to have a small cyst or tumor in their reproductive tract. You just never know! Another doe has issues with two litters, but then had her third successfully. No idea what the deal was there.