I think you don't have to worry about it. I made a really deep research and I can say that there is no electronic component in the active head restrain system. It is just a simple mechanic part that is activated by the weight of the occupant. In case of a rear ended collision, when the occupants body goes backwards, the head restraint goes forward. To protect the neck. I also compare the headrests with three brand new Rogues and two 2008 Rogues..they all move like the one I upload on Youtube...
It is just human nature. After the accident you though they are broken..but not. (and your accident was not rear ended type like mine)
http://www.nissan-global.com/EN/SAFETY/ ... /HEADREST/
The system is as complicated as the ones in Toyota:
http://www.toyota.co.za/ContentPage.aspx?PageId=127
After my accident I thought my is broken as well. I though it is a single-use safety feature, like airbags. But no. The owners manual doesn't say anything like "you should change them after a serious collision" and NissanGlobal website says "they will go back to their original position after a collision". The only question is maybe they are damaged. My previous car was a Renault (back I was still living in Europe) and the owner manual of that car says "after a serious collision you should let mechanics check the seat belts"....Yes seat belts are not single use security parts like airbags, but they SHOULD be checked.
But here comes the trade off...Would you really want those mechanics take your seat apart and change (or try to change) the parts and but them back together. While they are removing the seat God knows what other damages THEY will cause. So I, after making lots of research, decide not to let them touch the seats.