That being said, let's talk a little bit more about your logs.
1.) No one should get crushed by a direct rockfall. When the circle appears, you have roughly 4 seconds to get out of it. Don't panic, finish your cast, move. I've made my friends balk as I don't immediately move and boop out of it and watch it fall just as I've made my way out of the circle.
2.) Bats aren't dangerous unless someone falls to 35%. This becomes a huge problem when they're up and there's a stomp. Everyone goes to 65%, and with Rockfalls, can easily slip down. The problem with Paladin / Disc is that they want to get on top of the healing... reactive healing isn't their forte, especially on a spread fight like this. That's why they stack absorbs so they stay ahead of the healing curve.
Everyone should move in a bit before the stomp so a Disc can spirit shell everyone so that this isn't a problem. And that way you can get in some illuminated healing in too.
3.) How fast are your spinning turtles going down? This is kinda critical, because if you have people bouncing up in the air all the time, it really messes things up. Especially if someone falls low and the bats suddenly rip off the tank. You don't have a lot of slows in your group, so Earth Bind Totem and Curse of Exhaustion will be your friend. Slower turtles make the fight a whole lot easier. They become easier to dodge, and less of an issue during the rockfalls.
4.) What's your positioning like? Generally we try to keep the bats and the melee up front with the tank. This way they can move as a group for the rockfall. It makes it easier to kick the shells through the bats so the bats get the 25% damage debuff. (It allows me to make Healing Rain worth it since they're in that front area.) And melee with Cleaves can get bats and Tortos.
The priority really is Slow Turtles, Kill Turtles, Bats, Tortos. Kick Shells appropriately for increased damage on Bats and interrupts on Tortos.
5.) Keep the add tank alive. If there's going to be a stomp and bats are up, stun the adds. On my Shaman I use Totemic Projection for this fight. I just drop Capacitor, Magma, Spirit Link, and then project them on top of the melee / add tank and drop healing rain on them. That way, the bats are stunned, they receive 10% less damage from the stomp, and then immediately get some healing. I guess you could Barrier them if they're up there as a Disc.
But that's the point - stun those adds so you can get a few seconds to get people healed up. Tank should call it out and use a cool down. Disc can PW: Shield the tank for extra absorbs. Then just continue the AoE on them as you dodge rockfall.
You guys can do it! I think you just need to tighten up the mechanics. But it's my personal opinion that I think your Disc is a little too in love with DPSing and Atonement. It's good, it's great, but it's not the only way. And on this fight, if you want someone at 30% to get health and you crit? Your heal is halved and then you get the rest as an absorb... bats will still turn to that person if they're not above the threshold. It makes Atonement a little weaker on this particular fight.
Edited by Feythylan on 3/25/2013 3:06 AM PDT