But he's still a human being who feels like his failure caused the death of seven collegues, and the loss of 1/4 of the fleet.
He was really hurting...
Well, I hope the guy gets some help because its obviously not a call made by a single individual acting alone. The recommendation probably gets passed on by any number of people higher up. Technical decisions in any kind of engineering endeavor are often made by consensus, not a single, isolated person.
The earlier discussion about damage by the piece of insulation mentioned high speeds of the material and/or wing surface. Sure, they're all travelling fast at that point of the launch, but is not damage inflicted by the impacting object a function of the relative velocities? The familiar example is the image of a piece of straw driven by tornadic winds impaling itself in a tree trunk. A normally flimsy and light object driven to high speeds penetrates and damages a relatively strong material. But there the target is stationary and the moving object hitting with a high relative speed. If the two objects are moving together or at close relative speeds, is not the energy imparted somewhat reduced? I'm thinking here of the classical mechanics problem of conservation of momentum in the center-of-mass frame of reference. Unless there was tremendous slowing down of that piece of foam as it left the external tank, I can't imagine the relative velocities being too terribly different.