Wasted LB on Titan...what were they expecting to use, Healer LB3? Everyone usually just dies right after it (next stomp normally, but if the heal has really bad timing anything else could do it). And for a finishing melee LB...it really doesn't matter if its 2 or 3...you save what...two or three of his attacks? If the DPS is high enough, that really shouldn't matter at all...
I play it by ear, really...depends on how we're doing when the second Jail goes down. If we looks like we'll be good, no LB. If I want to play it safe, LB. If we need it...LB.
And you can always tell the group "I'm a DRG, its normally my job to LB the Heart. You never said anything, so I'm going with what most other groups do"; sure, it'll make someone upset, but maybe they'll actually say something next time...