The point about grounding cost should consider who and when the decision was taken, and what was the timing w.r.t. the progress of the investigation. When was it established that a camera could have contributed?
Even though the Voyager differs from the A330, are these differences significant regarding the control system.
Did MOD discuss the investigation and proposed grounding with the national authority or manufacture; noting that many more civil aircraft had been flying for a significant time and continued to do so.
I.e. What proportion of the responsibility for grounding should be borne by the organisation / their safety process.
Grounding / not to ground is a catch 22 for them, but having played safe you should not blame someone else to cover the cost.