The S-92 MGB lubrication system uses two pumps operating in parallel providing pressure, but operating independantly to scavenge their respective input modules. Normally, the operating pressure is around 55-56 psi.
The Norsk machine (referred to here) had a vespel spline adapter failure, which allowed the remaining pump to reverse flow the oil through the windmilling failed pump, in preference to the more restrictive pressure line - like a short circuit, it took the path of least resistance. The pressure dropped to somewhere around 5 psi or slightly less, which was, at that time, a LAND IMMEDIATELY drill. The crew were lucky that a platform was sufficiently close that they were able to land there instead.
That aircraft had the -101 pump. An initial fix was the -102 pump with improved finishing on the splines and an inspection requirement.
The -103 pump was then introduced which had a check valve thereby isolating the two pumps. In the event of a single pump failure, the remaining pump would produce around 17 psi.
However, an aircraft then had a pump failure (associated with the vespel spline adapter) and the efcet of not scavenging the input module became apparent through an action known as churning, whereby kinetic heating of the oil took place within the gears. The crew landed onshore.
An earlier event had also taken place where churning had manifested itself (212man's event?) but that was not associated with a pump failure.
A revised emergency procedure was introduced to address this phenomenon, whereby the engine of the affected module is throttled back to reduce the heating effect. the check valves were also removed from the -103 pumps to create the -104 pump. This was to stop the input modules being filled with oil so rapidly - which was overcoming the ability to scavenge by gravity drain. The remaining pressure of 5 psi is still sufficient to lubricate the MGB adequately.
None of the above events have anything to do with the "extremely remote" reference - that is solely referring to total loss of oil.
On aircraft did experience a total oil loss, following an oil filter mount cracking. There were maintenance issues involved, as well as choice of manufacturing material for the studs (titanium vs steel.) Both those issue have been addressed.
There have been cracked MGB casings around the oil galleries. the cracks have been small and the leaks very slight - certainly nothing that would lead to total loss in flight. Again fixes are on there way.
I hope the above cures some of the misconceptions and hysteria that seems to be abounding on this thread. It is all in the public domain and a little research and effort is better than the "someone once told me", "yeah, but I thought this happened" and "I'll pull a whole bunch of totally unrelated events and lump them with another statistic to prove a point" type comments we see above, by some.
If anything I have said is incorrect, then feel feel to correct me - as my name implies, it is not necessarily a type I have direct experience of.