Airbus Helicopters issued a statement after a relatively brief examination of only the partially recovered wreckage to the effect that their product was not at fault. The Norwegian air accident investigation team have since recovered more wreckage and have had the opportunity to examine it in detail, yet they have made no comment as to the precise cause.
In order to be able to make such a statement Airbus Helicopters either had immediate access to information that is not in the public domain, or, that this was a known problem that they knew could happen but on the balance of probabilities they thought unlikely.
From the victim's (and their families) point of view, it is immaterial if the gearbox split and severed a suspension bar or the suspension bar failed causing the gearbox to rupture. The end result was the main rotor separating from the aircraft and that is an unacceptable design flaw in any rotor craft.
It is immaterial if analysis shows that such failures can be expected only once in 100 million hours of operating. It has happened on at least three occasions in helicopters of similar design to date. The problem with probability is that supposedly rare events can happen in close clusters and when that happens the psychological impact is such as to overcome the rational thought process. People are disinclined to trust their life to such a machine, even though it can be demonstrated that such failures are extremely unlikely.
NASA had an enviable safety record when allowed a virtually unlimited budget, but engineering compromises and cost cutting measures eventually resulted in the loss of two space shuttles. Have commercial pressures reduced Airbus Helicopters to a similar situation where a known design weakness has been ignored because it was cheaper to budget/insure against a crash or two rather than fix the root cause?