And they were trying to correct their priorities by looking into the source control features, so I don't see how that's anything other than victim blaming for them not doing it sooner.
I would argue that it's common sense to at least make a point in time copy, to... IDK, a USB drive? Before trying to implement a new source/control system.
Just plug in an external drive, or a thumb drive, copy/paste, unplug it, then proceed with testing.
I don't see how anyone who values their time and effort could do any less.
As for the files, undelete is a thing, and it shouldn't be hard to do.
I once lost three hours of work early on during my learning, not much that I lost but it was a moment when I learnt a lesson. Never lost work after that ever.