It seems to me that the MCA is assuming that the broken stud bolt is the cause of the Newfoundland crash ,whereas if you look at the reports so far it may have just been a coincidence or a result of the crash.That Sikorsky put out a recommendation over a month before this accident that the bolts be replaced at some future point suggests it was not considered a fatal flaw .
Until the investigation has gone a lot further I don't think anyone should assume anything and certainly not lifting the grounding.