The crash was found to be not pilot error and the fault of a failed product that, had it functioned properly, would have made the approach and landing an uneventual happening.
Our tort/negligence system is based on fault, not who one is or one's status. Fault and the forseeability of the consequence of one's failure to act reasonably. In this case, the foreseeable result from a profit oriented manufacturer placing a defective product into the stream of commerce and it being used for the purpose for which it was intended and sold and nonetheless causing an injury by its unreasonable failure.
The jury did the right thing and so did the widow. That's the way the system is meaqnt to operate.
Finally, more generally, no piece of equipment that has ever been designed and built will function forever without failure, and to impute negligence to that failure is a distortion of the intent of the tort system.