The NTSB investigation performs the most useful service of all.
Absolution from blame for the guilty and persecution of the innocent.
But more seriously, hopefully they will not completely ignore Alaska Air's potential contribution to increasing the risk by continuing to fly after the series of warning alarms and restricting distance from land rather than imposing altitude limits and if that was a correct or erroneous policy to keep it flying, or pull for detailed inspection and resolution. They might also try to determine exactly where, when and how the installation of the plug went wrong, what point missed their QA, if additional or better located pressure sensors would be of benefit and verify that the design or fit up procedures will be adequate in future. You know. Document the big picture. In the end, it's seldom only one thing that went wrong, so it's important to understand the path the events took on its way to becoming a serious incident, then put up the appropriate road blocks to stop it from happening again.
--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."
