no what you really need is backups, isn't it? having an external hdd that you're backing up to is a lot better against data loss than putting that same drive into any kind of raid. (because now you truly have a copy, while in a raid it's still a single point of failure)
I can feel your pain on the ISP part though. (Haven't looked into this, but sounds like a zfs-job) Just saying that backups doesn't have to be offsite, but they do need to be separate from the original data medium. Going offsite is an important early step, but getting it on separate storage is the first step.
If anything, I would argue that especially in a homelab, the risk of misconfigurations or by mistakes when tinkering can increase by using raid. If you've have a couple of years of experience with raid and do not see my above argument, then please share your experiences.
I am sorry for this wall of text, your comment caught my eye while thinking about something else, tl;dr: raid is not a backup
If it's because of the lack of plan for the device, then if it helps, it's an extremely "in-character" and sensible action for the involved characters. It doesn't really need to be a plot device going forward, because the circumstances around it so far is pretty "complete" so to say.
I've tried to stay vague because of spoilers.