Hi PJ2,
Thanks for the link "The Effect of High Altitude and Center of Gravity on The Handling Characteristics of Swept-wing Commercial Airplanes"
"For a statically stable airplane the required column force, as speed varies from the trimmed condition, is less at an aft CG than it is at a forward CG. The minimum average gradient allowed by U.S. Federal Aviation Administration FAR Part 25 is one pound for each six knots."
Obviously AB FBW in ALT LAW does not meet that specification - and unfortunately the aircraft stalled. The known problem with the pitots should have been designed out much earlier.