"In spite of many months of investigations and now the AAIB preliminary findings, talking to my Flight Crew colleagues on the 777, none of them seem to believe that ice was the problem."
OK then: what DO your colleagues believe was the problem?
Flight safety is not decided by poll taking.
Questions are natural as this thread has proven. However, when Service Bulletins are issued by the manufacturers and/or authorities they should be complied with.
When the pilot community have questions about the application of a SB that is the responsibilty of the issuer to defend.
Many questions remain and hopefully many will be answered in time. However as some are answered then solid recommendations will be issued.