Camp Freddie raises an interesting point with respect to Flight Manual (RFM) Limitations.
In the US, the requirement to observe the limitations of the RFM are embodied in FAR 91.9(a) for all helicopters (thus, for those helicopters with more than 9 seats, the HV diagram is a limitation). For commercial operations in Europe (up to October), the same requirement is contained in JAR-OPS 3.005(c). Both of these regimes have appropriate alleviations under controlled conditions.
Up to October in Europe with respect to GA/private flight, the status of the RFM limitations is unclear (it depends upon the State's regulations). From October, the requirement to observe the limitations of the RFM is contained in the Basic Requirements - i.e. it becomes law and it applies to all. Unfortunately, the authors did not have the foresight to (or did not understand why they should) put a reference to applicable alleviations contained in the implementation rules (as is done in FAR 91).
Whether there was a requirement to observe the RFM limitations in this case (or others) will be a matter of reference to the ANO. Is it in the ANO or not?
Jim