You're assuming that the production company can afford to have someone around who knows how to put data on S3. My guess is that they outsourced this to the company who had the fired employee. Still, they should still have some kind of original files on some other medium somewhere... but who knows, maybe their production workflow revolved around this data-host. In which case they are really borked.
We have tons of decades-old video alive and well today. They may not have expertise with S3 but if they don't have the expertise to ensure robust backups, they're doing it wrong.
Yeah they may not but you have the weight up the costs of getting a contractor in to setup an almost fail safe system against losing probably millions of dollars of production.
I would assume it's more about people assuming something like this would never happen as to not justify the outlay of protecting against it.