Even if the bleed effect is cleansed and he only take 25k damage, that's 25k damage in the span of a global cooldown just from the boss's basic attacks. Tell me of 2 healers in an 8 man run that can heal 25k damage in one global cooldown. I can understand if the damage is from a mechanic like EC Kephess Breath of the Masters and such that can cause a one-shot, but that damage is from basic attacks only. Just seems like too much damage is going out from my perspective.
It's not actually his basic attack. Sweeping Slash is a periodic, high-damage attack. Not his highest damaging attack, but still periodic. 25k healing in one GCD is actually pretty easy for two commando healers (Advanced Medical Probe > Bacta Infusion x2 == 27k with average crits in exactly one GCD), but of course very few people run that comp. You don't actually need 25k healing though. Just be topped off before it happens and give your healers a few seconds to catch up:
Sorc: Bubble > Dark Infusion (3.7 seconds and an average of 15k healing)
Op: Kolto Injection > Surgical Probe (3.2 seconds and an average of 11k healing)
Merc: Rapid Scan > Healing Scan (3.2 seconds and an average of 15k healing); optional Emergency Scan for 6k more
Two coordinated healers can easily drop 30k on a target in about 3 seconds assuming average crits. More if their cooldowns are up, and more still if they're single-target healers (merc ftw).
Incidentally, the bleed was what was cleansed off of you right at the start of the log fragment you pasted. You had the bleed, and you must have had it for at least a few GCDs or it wouldn't have been up for Sweeping Slash.