Hi Machinbird,
To be fair, I think other posters have previously speculated on both slat/flap asymmetry and premature retraction of slats and/or flaps.
I'd be interested to hear your opinion, but it seems to me that the paragraph you quote was written by someone with limited knowledge - probably a journalist doing his/her best. It's partly incoherent.
However, I'm guessing that, in the event the crew detects asymmetry during retraction, there may be a way of freezing the surfaces in their present position. That could explain the extra switches on the overhead panel shown in this photo posted by Kulverstukas:
http://www.pprune.org/rumours-news/5...ml#post9621956
I refer to the switches just to the left of the L/G lever. Perhaps Kulverstukas will comment.
To take an admittedly distant example, and IIRC, the B707 has override switches for the inner and outer T/E flaps that freeze the flaps hydraulically, but enable them to be moved electrically.
Obviously IAS has to be limited if slats and/or flaps remain partially extended. That in itself should not compromise initial climb performance, but the stated necessity to limit thrust certainly would.