Without the manipulator arm (Columbia wasn't equipped with one for this mission) there is no way a weightless astronaut could have stabilized himself to do any useful work. Also, most of the tiles are tailored to fit into a specific location. Therefore, you'd have to (1) take a spacewalk on the non-existant manipulator arm to (2) assess the damage. (3) Then you'd have to return to the non-existant tile shaper inside the shuttle to (4) manufacture the tile(s) for (5) a second EVA to affix the tiles using (6) a bonding process that probably wouldn't work in a vaccuum or at low temperatures.
IMHO, their only hope was the space station, which this particular shuttle couldn't reach and was not equipped to dock with.
Given that the Space Station provides the rationale for the Shuttle, and visa versa, this accident is a management oversight of the first magnitude. The responsibility for this accident goes all the way to the top of NASA.
Not to mention that the Space Station is on a different orbital plane than the Columbia was...it's like trying to arrange a rendevous between a car on I-70 and a car on I-40.