If Riley died in Eclipse, how is he going to be in both parts of Breaking Dawn?

it's probably just flashbacks, they couldn't bring him back cos that'd be stupid. unless they forgot to burn his remains in all the confusion in eclipse, then he could...... hmmmmmmm.......

I think it might be a mistake because I just reread breaking Dawn and Riley isnot mentioned unless they are going back to the fight with the Newborns that has been mentioned a few times.