It's been my experience that the "extremely remote" alternate means of compliance is to be based on extensive in service histroy of a similar type. The S92 was a brand new type certified Cat A to FAR part 29!
GT, I'm assuming that SAC were using the Blackhawk history even though we all now know that the MRGB designs are quite different.
Wrt. the article written by Ken Armstrong perhaps he was alleviating to err on the side of caution i.e. don't rely on any run-dry time or glycol cooling or whatever the manufacturer tells you will work.
I myself as a PAX would rather take my chances with a ditching than an unknown MRGB real-time run-dry time with a full contingent of SLF, baggage, and whatever crappy weather the offshore throws at us.
Many lessons are to be learnt from 491 by all. Bashing a column based on data prior to the TSB report release isn't helping anybody. In fact IMHO the opposite is true as the column raises awareness again of the S92's MRGB limitations and the inherent issues in CRM, FSI, ops procedures and the RFM.
Safe flying
Max