The report is out on 11 November 2014 RLC ditching:
Bell 407 Power Loss GOM Ditching: NTSB NTSB disagree with RLC but are unable to pinpoint a cause.
There is also an article on cold weather fatalities (another RLC accident from 11 December 2008):
So You Think The GOM is Non-Hostile? Just how cold does the GOM get in winter?