If a tank loses aggro, whose fault is it?

[EorzeaHero69]

Someone mentioned about vote kicking the tank. That wouldn't be possible because he is paired with the other Black Mage. Unless I'm mistaken, you need 3/4 votes to pass yes (because you obviously can't vote for yourself)?

It's 2/3 people for 4 man instances, and I think 4/7 for 8 man instances (That includes the person who initiated the vote).

[ShinMetsu]

It's 2/3 people for 4 man instances, and I think 4/7 for 8 man instances (That includes the person who initiated the vote).

^ This :P
There is only 3 votes as the targeted person doesn't get to vote, so.. if there is 2 friends in a dungeon, they can always kick anyone.
If you notice there's 2 friends in a dungeon and an argument breaks out with one of them, in that case it's probably the smartest thing to just back off and comply to not lose exp/time!
Although sometimes not being smart feels better :P

As for whose fault, definitely the tank in this case. And don't worry about him defending his girlfriend, it's what most people would do.
Say anything and make up anything to protect their feelings.

My personal rules for DPS/Tank faults in dungeons are..
Tank is always at fault with randoms, except for...
DPS goes ham while you are still running ahead to pull more mobs.
DPS uses a heavy single target burst in huge AoE pulls. (Tank is responsible to respond to this though and get aggro back)

It's a little more complex in savage, along with NIN enmity dumps/shift as well as random or static, but that's not relevant anyway, i guess!