Well, what I have found is already quoted. In the condition summary, helpless is described for the condition of being unconcious and in that same summary states you have a Dex of 0. It does not state that saves work any different (IE, you don't get a reflex save).
The quoted text about evasion I think is misprinted (in the manual) as there is no backup for the implied statement (that you don't get a reflex if you are bound or unable to move).