Ending - beware all whom enter this thread, there be spoilers ahead
I was hoping that it was a different guy in the cage, that Julia Roberts had captured the wrong chap. When he sticks his hand out of the cage to touch Ejiofor's face, I wanted it to dawn on him that the guy in the cage was just some other dude, and that the killer was who he thought it was all along.
That would have given us more interesting options on how the story could conclude. In fact I was surprised it didn't go down that road.
I was never one to hold grudges. My father held grudges, I'll always hate him for that