They DID in fact hit 4 innocent bystanders. While I agree with TJ, it doesn't do any good if the laws are not enforced on police officers. They can, and should be charged with murder for things like this - but rarely are. They are above the law.
Masonite is a cardboard type product, although it's name is deceiving and you'd think it was a cement product. It burns very well, and I wouldn't use it for fireproofing. It appears that what you used is cement backer board like Durock or Hardie Backer, used under ceramic tile.
Ron Paul says the same thing, and he's a christian! He just believes in the constitution, and separation of church and state ...