You can bicker and argue about who healed who till the cows come home, but the absorb vs throughput, holy vs disc arguement has been tried and tested this xpac and the result is always the same, that disc comes out ahead in the vast vast majority of
realistic situations. My first comment on this thread addressed the reasons behind this in detail, but this article
http://lifeingroup5.com/?p=3686 , which I found while reading Sonnie's SoO review series on the method website, outlines exactly why absorbs are so powerful, and does a very good job of placing the blame squarely on the fight designers. Anyway, the point is that regardless of what kind of situations involving minimal healers, perfect execution etc, that you can invision to give holy an advantage, disc is still the more appropriate spec in every realistic SoO encounter due to fundamental nature of absorbs and the encounter design of SoO. However, the bottom line is to play to your own best ability, and if your specific situation, whether the result of experience, gear optimisation or attitude, is that you will heal better in holy, then by all possible means, play holy.
Also, im very interested to hear more about this inner focus bug