Only speculation, but this seems likely:
- High Fuel Load as Tanking Fuel into airport causing more then normal aft CG
- Pressure to land aircraft (fuel, weather, approach type, ...)
- Go-Around initiated
- Due location of engines (737 design) a high pitch is normal
- Possibly due to the fair amount of additional fuel carried and moving to an aft CG (fluid dynamics) an usually high pitch up occurs
- Possibly using Full TOGA instead of reduced TOGA causing additional nose up tendency
- Very high nose up instance established
- Rapid Speed Decay occurs in this attitude
- Large Forward Control column pressure to overcome high nose attitude
- Speed Decay results in stall with associated wing over
- Nose drops vertical, earlier nose down input would aggravate recovery efforts for crew
- No recovery height available for regaining speed and control
- Impact on ground vertical position unavoidable