/sit cause larger assist radius on rooted mob
 

Killing shadowed men....they con light blue so I root one which at that time does not aggro another that is close by. But when I /sit the one that was not aggro now aggros. This is all while at max casting range. It seems that the assist radius of the rooted mob got larger when I sat. I repeated this a few times to make sure it wasn't a once in a lifetime thing but it happened regularly.

Think thats always been the case. Once you sit you are effectively level 1, so now his buddy will help just as if you had cast on him as a level 1.

this is normal behavior. green mobs that wont assist their higher lvl friends will try to attack you if you sit while engaged with the higher lvl friend mob.