If the ditching was planned, then IMO, doing so without advising the NLK R/T man, with whom they were in contact, was the most negligent act, of a poorly executed flight.
And one can't blame Pel Air, CASA, the ATSB, or any one else for that.
I find it so difficult to believe that one could ditch and not tell anyone where, that I find it even more difficult to believe that the ditching was planned.