Picked up an N22 from Avalon and they made me do a rear cg flight by loading lead bars in the cabin. It was exciting in the turbulence and I needed care to fly it with the stick bumping the panel throughout the flight. They taught me how to recover (below). When I got it back to the airline I did the w&b calculations and found that the basic index they had used was wrong, by a considerable amount (calculations were wrong, and the index was actually a lot further aft). So the flight I did had been way outside the limit yet the airplane flew and was always controllable. However if you are not familiar with the condition, and do not know how to handle it, you could be in trouble. This is true of all light airplanes, and not only lighties. I have flown a HS748 so far out of balance (2000 pounds not manifested in the rear) I could not steer it on the ground (thought it was an over-inflated nose oleo causing the nose to sit so high). Singling out the Nomad is typical tall poppy stuff that I expect from Australians. Funny that; no other country seems to have that degree of cringe factor.
I was told the Sabah accident was caused by a load of tinned fish being placed in the rear locker without notifying the crew. The airplane was out of balance and if they had made a normal flapped takeoff they would have discovered the balance problem even before rotate, but they did a non-standard takeoff and the problem became uncontrollable when they put the flap down for landing.
Could happen to any airplane, but once again, any chance to knock the Nomad and out they come.
Anyway, if you are faced with a rearward balance problem (stick full forward and nose still coming up), you need to reduce the flap, reduce power and roll into a steep turn. Get the nose down (more than 90 degrees of bank if you need it) and increase speed. Use whatever altitude you have to do this. You will think that a high bank angle at low speed will cause the wing to stall, but if you do not react, the wing will stall anyway. Keep rolling, beyond vertical, until the stall buffet ceases. When the airspeed is up you will have enough elevator authority to regain control. Burn off fuel if it helps and move passengers and cargo forward. Land using no flap and a higher than normal speed. If the condition is bad enough, the airplane might tip onto its tail during the landing roll.
The auto pilot might hide the fact that the airplane is out of balance, and when the flap is extended it will just let go, leaving you to handle the problem without any warning. If you are prepared, it should be easy to recognize and easy to handle. Tell your passengers you always land that way, and remind them there is a surcharge for aerobatics.
Always use the correct configuration and technique for takeoff, and set the flap early (above 500 feet) for landing, since this condition can be masked if you are using higher than normal airspeeds. Some airplanes will develop a rearward cg as fuel is burned and you need to be careful in that case, especially if fuel transfers have been interrupted.