A quicker way to reset the aircraft when it tilts back like that is to go into map view and slew the aircraft around a little. It should right itself.
And just a bit of trivial info, I just came back from Hamilton Island, and while waiting for the A320 to taxi, I noticed, with a half full load of passengers, and very little fuel, the nose wheel of the A320 was about an inch off the ground while taxiing. So aircraft CAN tilt back a little. Couple that with scenery that can have dips and bumps in it, and you'll get a tilt back on the tail.