I don't agree; he also showed it against Hunt when the Samoan went on the offensive, and was caught with left hooks from Hunt while circling out from the cage numerous times.
Beyond this, Hunt was giving JDS some trouble early on by tagging him with the left hook as he ducked in to work his body jabs, although JDS must be commended for adjusting nicely by feinting his duck in to draw Hunt's left hook before then flooring him with that overhand right through the opening created.
Otherwise, JDS simply has not fought any other opponent who is skilled enough to successfully pressure him, which Shane Carwin displayed by bull-rushing dos Santos only to be sat down by a counter left hook. Chasing him is a terrible idea, but he can easily be backed up by methodical strikers who will maintain their stance.
Interestingly enough though Cain actually got nearly ktfo by a left hook on the way in during the very first round of their third fight as well. Guy just cannot move his head at the right times.