I wish it were those banjo bolts, like you said, easy fix. After reading that entire thread more than once, it looks as if that particular filter has been removed and the filter now resides in the other banjo bolt that supplies oil from the head. Follow the oil line from that same bolt you removed to where it enters the head, dat's da one! Don't know if they started with filters in both ends of the feed lines, (total of four), and reduced it to two, or if they just decided to move it to the other banjo. Subaru made a running change at the factory early 05', what they did, who knows? This would affect models after the change, so 2.5 turbos sometime in 05' and up.
Just checked, couldn't access the thread either.