Scoring medium hydration dough after it's been in the oven I've been using this setup for 60% hydration dough: 

20 mins in cloche, covered, 500°
10 mins in cloche, covered, 450°
20+ mins uncovered, 450°

For all intents and purposes, the cloche works like a Dutch oven, trapping moisture:




(You can see in my second photo my rescue attempt)

I've got a baking sheet with water to maintain humidity in the oven as I bake it. 

The problem I'm running into is that when I score the bread (1/4" - 1/2", single cut along the centre, trying my best for a 45° angle, immediately before it goes in the oven), the score actually glazes over, becoming part of the crust, and preventing the score from doing it's job of 'ventilation'. The first time this happened, my dough blew out. The next two times, I've caught it happening in the first 5 mins and re-scored it after it's been in the oven. 

So, two questions:


Is scoring bread after it's baked for a few minutes a common thing? Do bakers do this?
If not, what can I do to my baking method to prevent the score from crusting over?
It looks like there may be some misunderstanding about how the cloche is supposed to work, and what scoring will/should look like. I think the bread in your photo looked like it didn't need any further scoring. I think it looked like a great result, since there aren't any visible blow outs on the bottom.  If you preheat the cloche in the oven, and put the bread in, with one or two deep scores, you should get some spring and steam from the oven as the water escapes from the bread inside the cloche. This is what causes the wide opening of your score.  The fact that it doesn't look like the "leaf" or "lip" that professional bakers get is mostly due to practice with the angle/depth of the score, and likely the amount of steam that is in the oven.  The cloche will create some steam, but not as much as is in a commercial oven with steam jets.    I don't see anything wrong with your pictured loaf.  It may be different from what you were expecting, but I think it is perfectly fine.  There was probably no need to do the second scoring.