since he filed, he should wait for acceptance or rejection notice. if rejected, he can add it and resubmit. if accepted, he's out of luck. he will now have to wait until his return is fully processed - payment cashed or refund received, then he will have to go through the hassle of filing an amended return 1040-x. this can not be e-filed. if he has a state return that also will have to be amended and mailed.
