Scotsheli
I believe in credit where it is due and that is clearly with Shell Aircraft for ultimately inventing, inspiring, directing, funding and introducing HUMS, TCAS, Safety Cases, HFDM, QA etc etc. Yes, a few contractors may have done some detail work but that hardly counts and technically any innovations made during the term of Shell contracts belong to Shell. You are also incorrect on this issue of design approval as the aircraft equipment you mention has all been approved by Shell Aircraft.
SASless
The Nigerian competition was rigorously run, including a unique fly-off as you mention, and the best option, based on a complex series of evaluation criteria was selected. That aircraft, the EC155B was smoothly introduced to service by Shell as a clear demonstration of Shell's focus on safety as you say. This was the first use of a modern helicopter in the offshore business and was a great success as evidenced by Shell's excellent safety record in Nigeria since.