Whose bits are to blame?
I'm not an expert, but surely this problem is associated with the engine type rather than the aircraft type. So which engines are to be avoided?
I'm still not an expert, but surely it is a sealing problem in the engine - so whose oil seals are to blame?
And in one case I know of, the first exposure was unpleasant, but the second triggered an allergic reaction. End of career - since a third exposure could be fatal.
And serious thoughts about that pilot ever travelling as a long haul passenger.