The only scenario that fits the information we currently have is flight control failure/malfunction, specifically the trim/horizontal stab. The go around profile and speeds are consistent with a normal go around - initial climb, then shallower climb to accelerate - the ground speed data is absolutely consistent on this. Then all of a sudden, at around a derived IAS of 220+ kts, a nose over and then an avg of 18500 fpm. Two pilots in a low authority gradient environment and neither one takes control? I can't see it. In my mind they were attempting to recover.
Given the data we have at the moment, I would have to agree.
It’s all normal until suddenly it isn’t. In terms of acceleration, +2,500fpm to -18,500fpm in seconds is substantial. That’s a change in velocity of >100m/s in the vertical plane in a very short time which would imply considerable negative ‘g’, most likely outside the aircraft limitations and possibly enough to cause structural failure...