"Only the desperate would try to turn an incident caused by a maintenance error into an excuse to blame the manufacturer for a bad design. That's like saying it was MD's fault that the engine fell off of the DC-10 at Chicago, even though it was American Airlines that did improper engine changes.
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It was both, of course, re: AA191.
Redundancy in the power to the LHS stick shaker and the RHS stick shaker not being optional, to overcome both design flaws (in addition to no leading edge slats lock), would likely have broken the chain of causation (irrespective of the AA maintenance misbehaviour that caused the engine separation).
Always a chain of causation.......