From implementation point of view networks are asynchronous and therefore are always partitioned. We don't actually have a luxury of arbitrary CAP interpretatio

From implementation point of view networks are asynchronous and therefore are always partitioned. We don't actually have a luxury of arbitrary CAP interpretations, we can't know whether other nodes are available or not at any given moment. So instead we have to make requests to other nodes and always choose either to wait for responses (or more complex communications to achieve consensus) and get C or not wait for anything and get A, although each node can be a bit behind on updates from other nodes. Thus the CAP choices are pretty much about latency: waiting for globally visible updates vs not waiting and getting low latency. Both can be mixed in various proportions to get consistency with good latency, but still reasonable tolerance of byzantine failures.