My high school yearbook teacher once said to me that "if you can't write,
you shouldn't be an editor," or in this case a fan-fic critic. All I
suggest is that we should critique him, as fairly as he has on our works.

Your teacher was wrong.  Editing is like coaching.  Good coaches do not
need to have been good athletes and good editors do not need to be good
writers.  

**In this I would have to agree.  One of my editors (on my upcoming Sailor
Moon series) couldn't put together two lines of prose to save his life, but
he's one hell of a stickler for going line-for-line.  Being a good writer
to be an editor or a critic is nice, as is the athletic analogy, but again,
it isn't a requirement.

ja,
--Rob