Guild Wars 2

i tried samarog with pug team and believe this is a bug. when samarog hp reaches 30% instead of 1 person get the red aoe bomb and 1 green, everyone gets it and 1 green, this result to chaos and eventually party wipe. we thought it is the normal mechanics and we were trying to solve it because repeating the boss, everyone get red bomb again at 30% hp. after a few wipe at 30% we decided to disband. when i chat with a few people that killed the boss, none encounter such so i thought it must be a bug xD I killed this boss with another pug team later on. just thought to report this. sorry no video or no screenshots.