Helicopter VFR minima are not the same as fixed-wing. There are several differences. In the case of offshore, it depends on the company's ops specs. Most use 300'/2 SM for VFR, but some are lower. The FAA requirements are 'clear of clouds'.
Offshore OSAP approaches require use of radar in addition to GPS. The position of the approach target must agree between the GPS and the radar, and the radar must be operational to insure that there are no other targets in the approach area, or which cannot be missed by at least 1/2 mile. I know of no authorization for an offshore approach using only GPS.
The NTSB report and Crash's blog are certainly different. The term 'ballast' does seem more appropriate when reading the NTSB version. One can now better understand the post on the blog - very self-serving, ISTM, and perhaps not completely accurate.
If this flight had been done IFR from the beginning, it might have finished more happily. But a new crew, perhaps not IFR current, is often reluctant to fly IFR, and the lack of facilities makes it even more difficult. There is no radio or radar contact with ATC past the beach, in essence, and there is no weather reporting in most areas, so OSAP approaches are difficult if not impossible. The alternative is to file to a HEDA (Helicopter Enroute Descent Area), a location previously surveyed for having no obstacles, and descending to VMC there. The minimum descent altitude in a HEDA is 400', and the flight can continue VMC with weather as low as 300' and 2 miles visibility. That wouldn't have helped in this case, but having weather reporting and ATC communications, allowing an IFR approach to the platform, might have. All it takes to allow this is money - money which the government and the oil companies refuse to spend.