Now, there’s two things. First, if a tank is going to do “big” pulls, they need to make sure it’s ok with the group. Check with the healer etc. If the tank cannot properly gauge how well a group may function for pulls after 1-2… well they’re not… that good. I typically err on the side of caution and grab just a group or more. If the healer wants to do more I’ll go ahead and grab more depending on what the next groups are like etc.
Second, tanks need to make sure their groups are with them. Especially healers. If the healer is lagging for whatever reason behind (check their mp, ask if they’re busy, perhaps they need to get a replacement if the group needs to stop after every pull because of x y or z), a tank shouldn’t be charging ahead and the healer’s not with them. You’re dead without a healer.
Now about heals, I obviously don’t know exactly how you healed but did you get to put the other cooldowns to use even though Benediction was not up? Divine Seal, Presence, Regen, Swiftcast heals? The tank was dumb to leave without Protect and then to plop themselves into the spot to get vulnerability…? Come on. Typically a big pull will have the tank pop a minor cooldown or two (depending on how much they’re running) while the healer sprints, when the tank stops they pop a bigger cooldown (some PLD will pop Hallowed so you can start healing big time without worrying they’re dead before you cast). There’s no point to a holy stun if the tank is gonna die before a heal can help. If a healer tries to pop a heal at the tank, a stray mob may come at the healer’s face as the tank won’t always be able to flash every single mob before the stop.