I couldn't resist making Crum Bums miche either. Everything went perfect. I made two loaves, let them rise on semolina covered parchment on a cookie sheet. I had an appointment at noon so I planned to get them in the oven by 11:00 a.m.
I took my stone out of the oven, put the loaves in a cold oven, set it to 500º for 10 min. then down to 440º. All looked well through the glass door but then about 10 min. later I smelled something burning at the same time I saw smoke from the oven. The parchment was smoking and the bottom of the bread was black! I quickly took the pan/loaves out, put my stone back in and put the bread, which was risen, unto the stone. I turned the oven off and left them to fend for themselves, I had to leave.
I don't have a clue what happened. I think the bread is still delicious so I just cut the bottom off. The crust is dull but I'm surprised the bread did as well as it did. It must have finished cooking in the turned off oven. I didn't get back for several hours. I'm ready to try this again very soon....as soon as I find out if my oven is out of order or what.??