I’m not claiming it’s a CA system, and the terminology “partition intolerant” is not verboten by Kyle Kingsbury. From your link: “Specifically, partition-intolerant systems must sacrifice invariants when partitions occur. Which invariants?”

The answer in this case is that availability is sacrificed, unless Amazon is making a very misleading claim of strong consistency (per the submission title/link). So it’s CP.

In case “not fully partition tolerant” is what is throwing you off, all I mean by that is that there are likely network partitions of the S3 nodes that will not cause outward failure (e.g. partition of a single node), though some will (e.g. too many partitions to form a quorum, or whatever their underlying consensus implementation relies on).