On Couchbase 1.8 running as a memcached cluster is it possible for a key to revert to a previous value?

I’ve had instances of stored keys reverting to (sometimes much) older values, and can’t track down where it could be. I’m wondering if it’s possible for Couchbase to somehow revert to an earlier revision of a key, (e.g. the way CouchDB had earlier revisions way back when). I use Couchbase as a memcached cluster and have had some issues with nodes dropping out, and some autorebalancing, though that may be related to the notes being removed or re-added.