TD,
I think what Exrigger was trying to say was that not all IRs are raised because of serious problems. Often we will raise an IR to highlight potential problems - we may have noticed something before it became a problem and IR it to prompt the system into addressing it - and so that others can learn from our experience.
Everything from a lightning strike to a cut finger on a sharp bit of metal could prompt an IR.
Nobody from the aircrew side here is saying that we know what caused the loss of our friends, and your son. It is in our interests also to get to the bottom of things but, and it's a big but, lots of the posts on here are simply not accurate.
Keep strong
Kindest Regards,
Vage