Why is this hard to understand? The map is not the territory! Any data you didn't record yourself may not be complete.
If you controlled the firmware of a device that surreptitiously records more than it should be recording, would you show those "extra" recordings to the mark nicely chronologically sorted with the legitimate recordings?
If you were a criminal (or government agency) attacking these devices with bad firmware or buffer overrun, would you have even the slightest care about making sure echo.amazon.com is updated to show your eavesdropping?
// only five karmas and a username that is a googlewhack (!) bringing up exactly 5 posts and nothing else smells a bit like JTRIG
...I guess i just misunderstood the nature of your question. Yeah there's no way to tell if the history is everything they send or just the commands it heard. But at least it's something. Guess you're looking for something more along the lines of this type stuff
What about new versions of the firmware?