Tanks are having a really hard time to understand that they're not overgeared anymore and that large pulls are not a great idea when you're not overgeared.
And I had a great experience last night in my Trial Roulette (Ramuh Hard).
NIN: "Hi, I'm new here!"
DRG: "Same."
PLD: "No problem, it's an easy fight"
* adds appear *
Me (DRK): "Kill adds!"
* DRG and NIN proceeds to ignore adds and hit Ramuh nonstop *
* Party wipes *
Me: "Guys, we need to kill the adds, come on"
NIN: "Didn't you hear we saying that we're new here?"
Me: "Yeah, that's why I shouted KILL ADDS 3 times."
NIN: "I'm focusing on the fight, not in the chat log"
Me: "..."
Cleared after 3 more wipes.