With no time to pull free his sword, Garon pivots and bashes his shield into the zombie, hoping to knock the remaining unlife out of it.
OCC:
Shield bash with +3 power attack still (+10/+5 normally, +7/+2 with PA)
AC will go down to 20, 21 vs. the Goblin.
Shield bash vs. Zombie Ogre (1d20+7=20)...