At the time of the Qantas Airbus A380 flight number QF32 non-contained engine failure incident at Singapore, Qantas grounded the whole fleet. Later inspections by Rolls Royce found that over 20 engines had the same fault. The cost to Qantas was obviously high, but I believe it was the conservative decision to make until the full information was available as to the fault. Fortunately, it only took a number of days for Rolls Royce to ascertain where the fault was that caused the engine failure.
Hopefully we will get information in a short time as to the cause of the Longranger accident, and the regulators can make a well-balanced decision.