As I understand the oil filter problem, Titanium bolts were used on a component that had to be regularly removed and refitted as part of the mandatory maintenance regime. Whatever the history of Ti use in aviation may be, that approach is very very unwise. Only a matter of time.
From some anecdotes I heard:
The stud galling became a real issue because the removal cycles ended up being far greater than anticipated, not simply because of the use of Ti (however the S92 did go through a major weight-loss design optimization effort and it stands to reason that Ti was used here for weight savings).
Supposedly the oil being used was filtered to a lower degree straight out of the barrel than the element size in the MGB filter. This meant the filter popped almost immediately each time oil was changed or altered. This caused the removal and re-installation of the oil filter housing and associated nuts on studs with much greater frequency, greatly accelerating the wear from galling damage.
Due to the MGB lube system design assuming any leak would occur in the oil cooler circuit and not from any of the system behind the cooler bypass valve, when one of those studs on the triangular housing mounting pattern failed there was no way to isolate the resulting leak.
Subsequently the 3 stud pattern was permanently installed and the filter housing was revised to use a 6 stud pattern and split in half with the bottom half adapter never requiring removal.