Amy and Robert are holding hands at the beginning of the wedding ceremony. When Marie interrupts, they let go. The camera angle changes and they are holding hands once again.
When Amy is getting ready before the wedding, we see another woman wearing the same dress as Debra, presumably a bridesmaid. During the ceremony, at the altar, we see Robert and Amy, Ray and Debra, and Amy's brother Peter, presumably an usher. The bridesmaid is nowhere in sight. She is, however, spotted later at the reception.
The bride and groom are on the wrong sides. As they face the minister, the bride should be on the left and the groom on the right.
As the organ is playing the wedding song, the camera shows Robert and Amy on stage with the organ player in the background. The organ player is seated looking out towards the audience before the last note of the song has finished.