And another thing Caz.
If what you say is true, and indeed the flight could not be completed without IFR flight in the VICINITY of the Mull then:
1. The Planning was flawed.
2. The Flight Authorisation was flawed.
3. Therefore the Act of Negligence occurred before departure.
Isn't it strange the Board, Reviewing Officers, and everyone else for that matter, never picked up on this.