Hmm, how long did you have the pie in the oven ?
I'm going to guess about 3 minutes maximum....
edit: ah yes, scpizza, I just noticed the cheese is still basically not melted much, just noticed that after reading your post,
and the mushrooms almost look like they were put on after it came out of the oven, however those muchrooms are FULL of moisture,
so that could be the reason. The dough looks great though
here you can see my pizza as result of my experiment by using the electric oven at a very high temperature (842F / 450C degrees).