I've checked my logs for Focused Assault and they are 100% hits. I'll link a log when I get to a PC at lunch.
Sidenote; are you sure you can't avoid it - dodge or parry? I could've sworn i saw parries last night during FA, might've been her regular attacks though. Got no log to go through.
The boss does not perform regular attacks during Furious Attacks. FA cannot be dodged, parried, blocked, and neither can it miss. It is simply a test of the tank's EH.
Normal mode Hagara Focused Assault log from 1/11/12, no dodges/blocks/parries/misses.