@ Oluf Husted
Interesting site you have however you are starting to misinterpret AD's and connecting it up to BA38. You may be right (can't exclude any possibilities at this stage) but what you are saying can't be connected up with the evidence given.
Reading the report you could have seen that the engines weren't operated at Flt Idle and App Idle from F400 to 780'AAL. And for the many BA38 flights I have operated into LHR, a flight idle approach is VERY VERY unusual.
The reason for the AD from RR was because more engine data had been collected over it's running life henceforth they amended the ground procedures for core ice shedding.
One thing I would like to say though: Why does Cathay operate the EAI and WAI manually, where so many 777 operators don't?