The new instances in LotRO have an interesting mechanic, which I believe is called "terror". A character under terror will start running (fleeing) in random directions, and can possibly run into places it really, really shouldn't. Fire and shadow clouds, which can possibly insta-kill, are plentiful in the new raid, and in the later stages some trash mobs can also give terror and make you run into another room filled with enemies. The effect cannot be removed, but it can be controlled while it lasts.
Map "toggle first-person mode" to some easily accessed key (I still have the default, which is * on my numpad), and whenever you get the terror effect, quickly turn your camera to the direction you want your fleeing character to face, and toggle first-person camera on and off. This will make your character turn to the direction you want, and can be repeated as many times as needed until the terror effect wears off. Use it to stay in whatever range you prefer (melee/ranged), and also to avoid accidental pulls or running straight into deathclouds.
I'd often like to slap those players in Sammath Gul who let their characters run all the way downstairs during the third boss fight.