This discussion may contain spoilers!
I think I may have found something... Carver's name is William, or Will for short. I've just found a sound file called vox_zomb_Will_death.
The actual sound: http://vocaroo.com/i/s0NFCCcvWOAQ
What do you guys think of this? It doesn't really sound much like Carver, but then again, if it is Carver then it's zombie Carver. Then again, it could just be a voice actor named Will who voiced a zombie.