That maneuver is quite sharp and abrupt. It is designed to expose the underbelly of the Shuttle to the atmosphere. In this case the underbelly is not the soft part (but rather the extremely hardened and thermally re-radiative, Carbon Fiber Hi heat tiles)
That is also where the Landing Wheels are housed and to avoid problems with exploding wheels both here and in space, the wheels are deflated till just before landing. Some one of the astronauts sent a text message that there was a problem with tire pressure. Houston acknowledged that message and said your last voice transmission was not clear. That was the last transmission.