Originally posted by Sadako of Girth
He used Cain's distraction at the Nuke cannister to jump up on Cain's back severs his interfaces, rips his brain-jar out and smashes it, IRRC.
Yup:
http://video.libero.it/app/play?id=8a3b6940a64735d9227efaf2d30bec08
Video shows that Riddick doesn't have a chance in hurting Cain. Surviving a masive fall, being slammed into by a speeding Bradley APC and them shoving it aside. Also, Robocop is one seriously durable mofo as well.