How do you know that these tiles fell off over California?
I believe that astronomer who said that his telescope showed bright flares breaking off the shuttle over California. I don't believe that plasma trails would resemble "flares". I believe these "flares" were tiles.
Almost everything in life requires judgment. Some here do not want us guessing what happened. I believe that it's OK to guess as long as we're open-minded enough to change our mind if new evidence makes our guesses obsolete. If no one would ever takes guesses on anything, we would never accomplish anything. Just like it's our guess that supply-side economics is much better than government mandated wealth redistribution through the tax system. I believe speculative discussions also help to get to the truth. Sue me.