Regardless of the actual cause of the "accident", evidence has come to light that NASA knew of the high probability of tile failure at launch, and had devised NO RELIABLE MEANS to assess damage to the underside of the shuttle; and, thus, had NO WAY to determine the real-time necessity of mission abort. They got caught, pants down, p***s in-hand. A camera facing the bottom of the vehicle, attached to the tank-struts--or something like that--could have saved this particular crew. Instead, they relied on a computer model that told them that the shuttle was either OK or very much dead--two days after the information would have been useful. They crossed fingers, threw dice, and hoped for continued providence. OOPS.
Then there's the fact that they had neglected to provide for a "plan B" if the orbiting shuttle couldn't re-enter safely. These guys are smart?
In my mind this was inexcusable negligence--athwart the common sense available to anyone, and certainly not up to the standards set by the early mission directors. I expect better.