I don’t see what the photographer missed – IMHO, from the description, it appears that the father’s actions were completely extemporaneous, taking everyone by surprise. I’m not sure how any photographer at a ceremony could be prepared for such an eventuality.
As a hobbyist, my eyes do not see a missed opportunity capturing the moment, and neither did quite a few hundred thousand others.
But seriously, do wedding photogs run into such situations at the ceremony usually? Serendipitous, fast-paced moments at a carefully choreographed – normally slow-moving – wedding procession at which most families will say “Thank heaven he caught that!”