This is a simple pic of SNE cut out. For some reason the orange LSF topic has gone AWOL on my laptop. The link in question must not be fitted to the earth bar.
I have watched various DNO jointers and linesmen making off joints over the years, the amount of insulation on the neutral strands never seems significant and more like identification by colour for the strands that need to go into the neutral terminal rather than insulation, leaving the other strands to go into the earth terminal.
But I suppose it does not matter if the neutral strands are not fully insulated from the earth strands in the DNO cables as they are both bolted down to earth and the neutral will never be switched out or isolated out from the earth strands as the DNO only fuse the live phases.