"It does if you cannot fly over a built up area by being in experimental category."
This had occurred to me, but why fly over either a built-up area or the sea while performing development test flights? From Google Earth there would seem to be no shortage of open land between the concentrations of buildings.
The answer to the question about lifejackets should clarify whether the test flying programme was intentionally being performed over water because of unavoidable built-up areas.
Again, it would be interesting to know whether the young woman was an assigned crew member and whether she was covered by insurance.
NDT carbon structures would apply after heavy impact with land or water and doesn't address the question of whether the aircraft ought to have been so far out from the shore.