It was the wrong call and wrong interpretation of the rule. The refs stated that they both had control of the ball at the same time, where then it is given to the offense (kinda like the tie goes to the runner in baseball). Seattle really didn't have control of the ball. Unfortunately with replay there was no way to disprove this as it is a judgement call.
I think everyone has been waiting for the replacement refs to really screw up and cost a team the game. This happened for Green Bay and it can be debated for New England on Sunday night (field goal for Baltimore went over the post). In my opinion these refs need to get more consistent and get more control over the game. There are a lot of heated instances on the field and some cheap shots happening that I think would be reduced with the real refs. I am waiting for someone to get seriously hurt because of the lack of control by these refs (What happened to Oakland's Darius Heyward-Bey is a good example).