Ssyre popped the ring, bomb 1 was still alive when ring exploded. There were 2 targets in range of ring pop so the dmg on each was divided in 2. Whoever pops ring first gets the buff 100ms earlier and explodes 100ms earlier. Ssyres ring split into the bomb overkilled it, everyone elses ring fizzled. Doesn't show explicitly in the log but it's obvious that's what happened.
Damage dealt while ring buff was active:
https://www.warcraftlogs.com/reports/9P ... d=15775021
Damage the ring pops did:
https://www.warcraftlogs.com/reports/9P ... 6%7C187620
795 ring is 43.7% damage amp/explode.
Xealouz 6.81m damage dealt, x0.437 = 2.975m / 2 = ~1.49m which is exactly how much dmg his pop did
Same for everyone except Ssyre, ring dmg halved.
We missed out on 15m dmg from ring fizzle, boss has 200m hp, so 7.5% of his HP.
Boss had 30m HP when he cast Blitz @ 1:06
No deaths until Dave at 1:00
Our dmg meters at the point he blitzes
https://www.warcraftlogs.com/reports/9P ... d=15825939
Not close to an ideal comp but if ring didn't half he'd be at 30m - 15m = 15m hp or 7.5% hp, so we'd still need to squeeze out 7.5% more raid dps to kill him before blitz goes off.
TL;DR kill bombs faster and do 7.5% more dmg for clean Iron Reaver speed kills.