silverstrata, I noticed (that flaps) were retracted but that in itself is not evidence of anything other than "retracted flaps".
Not quite. On the CVR we have a "speed" call, and then a surprised exclamation about "flaps". I would say that is
prima face evidence that there was something unusual or unexpected about the flaps. One possible unexpected flap condition is the flaps being retracted early, with insufficient speed. Another could be asymmetry, but most aircraft will lock automatically before an asymmetry develops.
Unexpected early flap retraction is the front runner, in my opinion. And it happens. As I relate above, there was a UK Io-co who had an acceleration call of "flaps up speed", which predictably resulted in a couple of inadvertent early flap retracts.
Thanks for the screw-jack image, Kulverstukas - that is an impressive array of hanging ironmongery. A most informative collection of pictures.