Actually a holy light from a well-geared holy Paladin will crit for 9k to 11k on me quite frequently when I have devo aura up. A FoL hitting for this much even (or perhaps especially) on a lower level toon would seem ridiculous and probably is a bug. Why heal a level 30 with 1k HP for 9k? Makes no sense to me.
I have run many heroics lately with myself (Prot Paladin), a Holy Paladin healer, a Ret Paladin DPS and an Enhancement Shaman. (Plus a hunter for additional and totally unnecessary DPS just to fill slot 5). The Holy Lights from the Holy Paladin hit me for 10k+ a LOT with this setup. We also finish heroics in 0 time with almost 0 downtime even after the 3.0.3 nerfs. Having Devo, Ret, and Conc Auras up with 3 Pally buffs and everything the Enhance Shammy adds and Trueshot Aura from the hunter is just ridiculous. I am really enjoying this for the next week!