As there are relatively few photos in BREAD, this may be exactly how the miche should have turned out... however, I suspect not!
Not sure exactly what went wrong, but I found the dough terribly wet and I think, with hindsight, this may have been one of those occasions to "correct the hydration by adding water or small amounts of flour". Alternatively, my substitute for the high-extraction whole-wheat flour may have been at fault: 45% wholemeal wheat, 40% wholegrain spelt and 15% strong white bread flour.
I may try this again later in the month if I can get a good idea how the rest of you get on. For now, our bin has acquired some new ballast!