Pablo, I'm no aircraft technician but from the photos published by EC, at modest magnification, the corrosion on the failed shaft was quite obvious compared to the smooth surface of an unaffected shaft.
I can't immediately find an SB requiring inspection of the surface for corrosion, but I do recall EC asking all the operators to look for it. Its such an obvious thing to do that I can't imagine that EC would not be sure that there weren't corroded shafts still in service, or that if they had omitted to do this, that EASA and CAA wouldn't have required it anyway.
If dripping oil is an issue, just remove the sump and leave for a couple of days until the drips stop - after all, these a/c haven't exactly been busy recently!
Last edited by HeliComparator; 4th Aug 2013 at 19:33.