Re: Efficacy of warning messages
Cue a 30GB disc fragged into same-sized chunk with helpful names such as filexxxxx,frag where
That sounds like FAT to me. Never had such calamities with NTFS, except that time I was using a slightly faulty drive (with early onset dementia).
In any case, what was the alternative (to pressing 'yes, fix it')? As I recall, with FAT chkdsk would produce those files when it found clusters marked as used, with no directory entries pointing to them. If the original directory entry happened to be in a now-deleted directory, the cluster containing that directory could very well have been overwritten and since released. Pretty much a fool's errand to piece it all together.
OTOH, IIRC each cluster entry (in the allocation table) would point to the next cluster. So chkdsk could've checked "is the next cluster in use by a different file by now..?" and made a more educated guess. If caught early, the next cluster would most likely still be intact. I'm a bit surprised that chkdsk did not do that for you. (you mentioned the files all had the same size, presumably reflecting the cluster size)
OK, asked differently: Was there any chance that you would have researched this deeper, used a different computer to download a better tool and done this properly? (basically the original disk should've been put in forensics read/only mode to not corrupt it further)