Well, it's possible that the same whatever is preventing the restore from succeeding each time.
But as I said, if he followed all of the Rockbox installation instructions, and that didn't work, then restored and that didn't work as well, by that point the options are much more limited, since the Rockbox installation method doesn't involve iTunes or Apple Restore at all.
Of course, if he screwed up part of our installation instructions (also possible) then the two things are different problems entirely.
He should probably try restoring his iPod on another computer, you're right.