Some comments from the Peanut Gallery:
1) Lu, "Spanwise bending" is not lead-lag. We use the term "flatwise" to describe upward bending in the flapping axis, "torsional to describe the twisting of the blade around its long axis, and "edgewise" to describe bending in the lead-lag direction. Spanwise is the direction where the centripital force (please, lets not go there!) is exerted, there is no "spanwise bending"
2) The main reason why this AD was issued is because when an accident happens, for whatever cause, the lessons learned are spread far and wide to help us all. The cracks in edgewise bending at the root are called the "failure mode" of the blade, or at least one of them. The location, growth rate and symptoms (vibration) are all great knowledge for the grass roots folks to store and use, as this knowledge can help prevent the next accident.
3) Having sat in grave meetings with our experts in review of accidents, I can assure you the designers and managers take very seriously their responsibility. Nobody I know of in this industry has a casual attitude about this stuff. Too often some person pushes the theory that big mistakes are just passed over, professionals rely on bluff and legalisms to avoid facing the truth, and known flaws are just glossed over by uncaring faceless minions who chase the dollar. That couldn't be farther from the truth.
4) Regarding legal coverups, the law specifically absolves a manufacturer who improves a design from using that improvement as proof of a mistake in the first place. This is a piece of wisdom that prevents the legal system from stiffling improvements, and actually impeding safety and progress. As long as the original designer used state of the art practices and dilligence in the original design, improving that design, even for a failure, is not proof of negligence (Flying Lawyer, did I just step on your turf?)
5) I know this is true for the big manufacturers, whose engineers and test pilots I work with regularly. From what I have read and seen of the smaller outfits, I am also sure it fits: We love flying machines, we try to make them as best we can, we test the heck out of them, and we fix them when they need it. Many of the professionals in the design teams are pilots themselves. We pass on the painful lessons we learn, and we pass on the lessons others learn with them. We rely on all the folks who put the machines to use for our livelyhood, our reputations are our foundations. We also respect the trust our customers place in us.
6) Some advice: when you read some poster criticizing a manufacturer, an operator or another pilot, or a regulatory agency, use the facts provided, learn from those facts, but take the evil motive and stupidity comments with a skeptical eye. President Harry Truman put it well in a letter he wrote, while President, to a reviewer who criticized his daughter's piano concert. "Some day I hope to meet you. When that happens you'll need a new nose." Were I Frank Robinson, I'd be looking for a few folks....