Journal-guided RAID resync

Aaah, I see (actually whenever you mention this I get it for a few minutes
and then it blurs out of memory again). Yes, that makes sense: if you
don't lose a disk, you have two intact stripes and one stripe containing
not-yet-written garbage: whether that's the parity stripe or not is
immaterial.

So the thing to be worried about here is that RAID-5 only really protects
you from a single disk failure if your array is not being written to (or
is battery-backed).

And I suspect this is the case the article was discussing.