The log looks a little odd due to the timing of the stun wearing off before the damage occurs. Assuming this is a lag issue with the combat log, it is possible that the 1 point in Mental Defense (15% less damage when stunned) I have in my spec might be the difference since it looks like the stun is applied before the damage occurs. If you have that point as well, then I'm not sure.

At this point, I think logs are needed. As indicated before, as a Balance specced sage, I was able to survive it in full 72s with my own bubble (albeit very little health left). Perhaps also double check your spec to make sure you are specced into Jedi Resistance or Telekinetic Defense.

Usually stationary by the time he lands.

Not sure what you are doing differently then. I was in full UW (including relics) the first time we did that fight and with my bubble, as a balance sage, I could survive it. I came out of it better if our healer bubbled me, but I was surviving it even with my own bubble.

Sages do seem to get hit worse than other classes by this ability due to our light armor. However, it is survivable if you are in full 72s with a sage bubble (one or two 69s is doable, much more and you are risking death as a sage) With that you will survive, though be at low health. A couple things: 1) If you are a dps sage and have sage healer, make sure they bubble you since their bubble is typically better. Of course you need to be at 100% following the hit. 2) You can use Force Barrier if it is up. Depending on your group composition, there are some ways to minimize the need to use this earlier in the fight. 3) As a dps sage, jedi resistance can help a little bit as well. 4) make sure you really are min-maxed. Some people are still using an old (level 50) relic, but claim they are fully 72, and that is a large loss of endurance. Double check that you really are at the proper health level.