This fight has being discussed extensively. I don't think Bioware has said anything official about this. Right now this fight is pretty much a RNG dependent/gear check/reaction time check. It does seem like a bug though with how much damage it is done.
1. RNG dependent - There is no fixed % when Revan does his force lighting. All you know is that he does it soon after Force Storm. The exact % tends to depend on your DPS. For us 35% always worked. If you time it wrong, your cooldowns will have expired by the time it does tick or you didn't had a chance to press it yet. Kind of trial and error process.
2. Gear check: The first tick of lighting does about 17-18 k with all defensive cooldowns active. If your tank is undergeared, he/she won't even survive the first tick.
pay attention next time you do it.. it deals 73 200 something instantly on the first tick.
3. Reaction time: Whoever is doing the interrupts need to interrupt it as soon you see the cast bar. If you are by even a second then the 2nd tick will kick in and you can kiss your tank byebye. What is more, if you do miss the interrupt and Revan has killed your tank, he will switch right away to another target and subsequent tick will kill them. You also need someone else on the 2nd interrupt because Revan will recast his force lighting 4 seconds later. Usually someone dies to the 1st tick of this as well.
and to answer the interrupt i instantly interrupted when the force lightning came up just as the cast bar showed up and it still 1 shot the tank + healer and the other dps even with being interrupted instantly..
what im trying to point out is that even if you had a machine doing the interrupt the first tick goes off for 73k .. you can fully avoid it with an assassin shroud but since he casts it more than once thats out of the question at this given time
Having said that i do appreciate your attempt to explain the fight for me wich im in no need off but still a nice gesture if i had no clue what i was talking about.
what im after is either a confirmation of it working as it should or that there is something wrong with the mechanic on revan
and in comparison to gear check we clear black talon on a daily basis hard mode in around 25-30min without the last boss enranging by far