Rifraf - oil pumps are driven from a single gear but not using the same part of the teeth, so eg if one pump seizes and strips the teeth, the other pump isn't affected.
I am amused by VL's foot shooting where he explains that the S92's pumps are independently driven from the same bevel gear..... Dur ... doesn't that mean that they also have a single failure point - the bevel gear?
It would be nice to have no single point failures in a heli gearbox but That is not really feasible. They all most definitely have a big single point failure item and that is the main rotor mast!
I think one has to distinguish between a single point failure that is catastrophic - eg the main rotor mast, vs something like oil pump drives the failure of which, as has been recently demonstrated twice, is not catastrophic.