I expect multiple people from Morton-Thiokol would have been very eager to point that out . . . if only there hadn't been incontrovertible evidence that the explosion was in fact caused by one of their faulty O-rings.
The O-rings were just fine. The launch occurred well below their minimum rated temperature. That's why the engineers refused to buckle under the full weight of NASA management and didn't sign off on the launch.
(OTOH the joint design wasn't all that great, propellent pressure tended to force the joint slightly open, rather than crushing it closed)...