Having worked on a number of similar studies I can only tell you that the most important lesson is to define the taxonomy or data collection definitions in such a way that they lead from an input to a useful output.
It does no good to place raw undefined data in front of people whose vision is only of the clouds in the sky without the experience to define the weather.
The first thing that comes to mind is questions about objectiveness of the data collection boundaries and how much subjectiveness is included i.e. by sampling opinions rather than defined definitions of on-off switches in the data.
Having no particular insight into the subject report I only have a question mark here and not yet an opinion.
On the other hand I deplore the premature release of data that has not been analyized by professional safety experts to the level of pointing at updating wide ranging recommendations for improvement in the bottom line which is less accidents/incidents.
If this study doesn't meet the criteria for advancing safety recommendations and at the same time leaves both the public and the professionals confused then NASA may have difficulty in getting funding in the future.