The nasty bit you speak of is split brain, and it's addressed by C. C says that if you read you always get the last thing written. If the nodes can't communic

The nasty bit you speak of is split brain, and it's addressed by C. C says that if you read you always get the last thing written. If the nodes can't communicate and someone does a write then the other half can't return what was written, so CAP is broken.