I have experience with the 737 but only the 400. However if the aircraft in question has the same autopilot, there is an issue that may be involved.
The Boeing 737 introduces a nose up trim bias at 400ft radio altitude. The system is fail passive and uses this as a safety feature. If the auto-pilot should disconnect below 400 ft due to a fault, the natural tendency of the aircraft will be to start a climb away from the runway. The additional back trim is also useful in the flare mode of the auto-landing process. Gotcha is in attempting a go-around manually after the auto pilot has introduced this trim. (following taken from Eric Parks notes at US Airways in 2002)
Remember that an Autoland uses an Auto Go-Around, you should ONLY press the TO/GA switches to initiate an Auto Go-Around. At about 400 ft. the autopilot will greatly increase back trim on the stabilizer to ensure the nose will come up in the case of autopilot disconnect. If you disconnect to go-around you will have a huge amount of nose up trim to deal with (bad thing!).
In short, DO NOT DISCONNECT the autopilot intentionally to go-around or to land. The system is designed for an Auto Go-Around and Autoland only. If the Captain sees the runway for landing just call LANDING and let the autopilot continue to land. If the Captain does not see the runway just press the TO/GA switches and begin the go-around procedure on autopilot and autothrottles. Autopilot should be disconnected AFTER landing (Auto throttles will automatically disarm after landing).
If this incident crew had forgotten about this then they could be "along for the ride", as the aircraft has a very strong pitch up tendencywith the application of full power.