Here is something interesting:
My rear hatch latch mechanism broke on my way home from buying the truck (a 2011).
I too, noticed, and also found it strange that there was no way to exit the vehicle from the rear interior. I didn't think a car could pass safety inspections without that?!
I called
@beno , and he shipped me a brand new mechanism. Now heres the funny thing: the new mechanism came with a piece of colored (either yellow or orange (I don't remember)) 550 paracord that was attached to the inside of the mechanism. I found that if the lock was engaged, you could pull the paracord, and the latch would unlock. My 2011 broken mechanism did not have this feature.
So, I can only assume that you could drill a small hole in the rear plastic panel covering the latch, and have the paracord poke out, and looped, so you can grab and pull in case of an emergency.
Now, what, or why did Toyota start pulling that emergency cord on the mechanisms, and what do they expect you to do with the cord???