Wondering if I'm the only one experiencing this or not.
I run a Jedi Sage healer, and set my focus target to either my companion when questing or the tank when in groups. I've tried this with several different keys and mouse buttons set as the focus modifier key.
Problem: Typically I pre-buff my tank or companion with Force Armor and Rejuvenation prior to any pull. If you hold down your focus target modifier and cast force armor, it goes off no problem on your focus target. I then typically hold down the focus modifier key and spam Rejuv so that I can maximize time between cast timers. The problem is that if you start spamming Rejuv prior to the GCD finishing, even though my cursor is still blue (indicating that I am indeed still holding down the focus modifier key) it casts Rejuv on me as soon as the GCD is up. This will happen with any combination of healing abilities. Press modifier key, cast spell 1, start spamming spell 2, then release modifier key at the end. Spell 1 will be correctly applied to your focus target, spell 2 will be applied to yourself.
If you hold down the focus modifier like in the above example but don't spam and patiently wait for the GCD to finish, then cast, it works as advertised. This seems like a bug to me, and prevents maximum efficiency in cast timing, which can be important in critical heal situations. You don't want the second spell to go off on yourself and miss a heal on your tank.
This happened prior to and after today's patch.