If they HAD started and taxied with the Gust Lock inadvertently engaged (contrary to the checklist) and then only noticed it that had been accidentally left on and so then released it while hydraulic power was on the flight controls (again contrary to the AFM) is there any chance that the Gust Lock throttle pin could/would release and not the mechanism that locks the flight contols?
I did read a comment by a pilot who flies the type that an engine start with the gust lock engaged would require shutdown, disengage the lock, and restart. Wasn't clear if that was required procedure (AFM), company SOP, or personal opinion. He was commenting on this accident, and sorry can't supply a link, may have been AIN or Avweb.