+But the object storage API probably provided a way to edit the metadata and update the last-modified time, right? (The analogue of `touch -d` on Unix-like systems.) This shouldn't even count as a fourth–fifth coverup; it was something he should have included in his coverup script.
+
+Was there anything else he was missing? The object storage cluster did have a optional "versioning" feature. When activated for a particular bucket, it would save previous versions of an object rather than overwriting them. He had assumed versioning wasn't on for the bucket that Multigen was using. (It wouldn't make sense; the workflow didn't call for writing the same object name more than once.)
+
+"I think I get the idea," said Jake in his attentive student role. "I'm not seeing how that helps us. Maybe you could explain." While she was blathering, he could multitask between listening, and (first) looking up how to edit the last-modified timestamps and (second) double-checking that the Multigen bucket didn't have versioning on.
+
+"Right, so if a model is behaving well according to all of our deepest and most careful evaluations, that could mean it's doing what we want, but it could be elaborately deceiving us," said Chloë. "Both policies would be highly rated. But the training process has to discover these policies continuously, one gradient update at a time. If the spectrum between the 'honest' policy and a successfully deceptive policy consists of less-highly rated policies, maybe gradient descent will stay—or could be made to stay—in the valley of honest policies, and not climb over the hill into the valley of deceptive policies, even though those would ultimately achieve a lower loss."
+
+"Uh huh," Jake said unhappily. The object storage docs made clear that the `Last-Modified` header was set automatically by the system; there was no provision for users to set it arbitrarily.
+
+"Imagine you're training your AI to act as a general home assistant, to run everything in a user's household in a way that the user rates highly," Chloë continued. "If—I don't know, say, the family cat dies, that's a negative reward—maybe a better feeding schedule or security monitoring could have prevented it. But if the cat dies and the system _tries to cover it up_—says the cat is out for a walk right now to avoid telling you the bad news—that's going to be an even larger negative reward when the deception is discovered.
+
+"Uh _huh_," Jake said, more unhappily. It turned out that versioning _was_ on for the bucket. (Why? But probably whoever's job it was to set up the bucket had probably instead asked, Why not?) A basic `GET` request for the file name would return puppies, but any previous revisions were still available for anyone who thought to query them.