[ogurechny]

Let's assume that they did change the course when they were sure they can do that.

Pilots can't look at the rear view mirror, and see the whole plane. Accident reports on engine malfunctions routinely mention that someone had to check their appearance through the passenger window, and relay that to the pilots. In case of a blast so severe that the door flies off, it is safer to assume the worst. Say, that part of the plane disintegrated because of sudden collision. In such conditions, indications on what works and what doesn't are probably really messy and unreliable, and there can be not enough means to control the plane properly. Lower the nose too much, and you might not be able to pull it up any more.

Pilots probably did checklists with one eye on the instruments to check that they were not losing speed, that angles were correct, autopilot inputs resulted in stable flying, and so on, and deduced that everything still worked. By that time, they were probably informed that the plane was seemingly intact, although with a hole in its side.