The client uses the same error code for server's and its own OOM errors

The function libcouchbase_error_t map_error(protocol_binary_response_status) which maps protocol error codes to client's:
https://github.com/couchbase/libcouchbase/blob/master/src/handler.c#L38

One of the cases when the client returns the same error code when it cannot allocate memory:
https://github.com/couchbase/libcouchbase/blob/master/src/handler.c#L128