We learn something new everyday, who knew video cameras retained video when you don't have a subscription - I wonder if they were turned on because free plans still keep recordings. They say TV's record you too, they probably don't want to show us those videos :)
“They say TV’s record you too”
They may record what you watch, but they don’t have cameras (typically).
Not sure whether the recovered video was stored on the door camera or at a Nest data center. We have a Ring subscription that stores the videos for 180 days. If we did not have a subscription, then the videos are not saved. I suspect, however, that even if the videos are deleted from the data center, they can still be recovered depending upon the number of times they have been over-written. I have used data recovery software on many occasions to recover files that I have accidently deleted from my recycle bin. Even though the data was "permanently" deleted from my hard drive, it is still there and recoverable until overwritten on the drive by new data. This is why many apps that wipe hard drives run seven cycles of random numbers, letters, and symbols to prevent deleted data from being recovered.