Legal Question in Family Law in California

You don't have any way to invaldiate the service. There is nothing invalid in what you describe. An OSC in many cases must be served the same as original papers. In addition, you never are required to serve the attorney, that is just to make things easier and because the attorney's address is the address of record for your "side" when service is by mail. You can always serve the other party directly as long as it is by a process server. As for the service pages being filled out, they are not filled out on your copy, because they would be a lie if they were filled out before you were served. The service pages say how and when you were served. Unless the process server can move through time, there is no way to honestly swear how and when they served you until after they do. So they fill that out on the proof of service that is filed with the court after they serve you.