looking specifically at fcob, there's a lot of situations where truly good play can be adaptive if someone fails their job:

-wrong way on tethers? compensate or kill your partner depending on whether or not streams will cross
-<insert t10 mechanic> here? holmgang, hallowed ground, heavy use of mitigation buffs can save a target that's going to fire electric burst. be ready to accept losses and top off for electric bursts if you're having problems, you're i~125 now, n b d
-bad brand touch? are you twelve or something just pass it back to the designated target(s) next flames cast
-never forget that anyone can touch bluefire
-never forget that anyone can be in the fountain of fire
-never forget that basically anyone can do any t12 mechanic with sufficient healing

-why am i a hildibrand

also: if your healers are playing catchup and can't prep for high raidwide damage like nerve cloud, flames of rebirth, etc, never forget that you have a tank lb (not really applicable for giga flare since you need to save meter, but that's because bahamut is designed to be a fight that tests your ability to stay consistent)