Sounds like both the Tank and the other BLM's weapons were broken.. That or they were just using extremely outdated gear.

There is practically no way a BLM sitting there in Umbral Ice will pull hate with Thunder + Thundercloud Procs - even if all the tank is doing is spamming Fast Blade/Heavy Swing/Hard Slash in tank stance.
Unless the Tank's weapon is broken and they are doing practically no damage.
There is practically no way a DPS will not pull hate if a Tank has a broken weapon - unless they too have a broken weapon..

Even if neither of them had a broken weapon, it is indeed the Tank's fault.
DPS just flat out shouldn't be pulling hate unless there is some crazy iLvl difference.

I would love to see the reaction of the poor DPS that joined that run after you got fortunately removed.. I would have been happy to get vote kicked from that mess.