The official report will be available in a month or two that will go into more detail. He may not have been attacked by the grazing bear he was photographing. This attack was predatory in nature and more info will come out as to what condition the bear was in. This is not normal behavior for a grizzly. They usually attack till they feel the threat is neutralized, then leave. He may have been in a fight recently or could be an old timer that was in poor shape and was having trouble finding the necessary food sources. Wrong place at the wrong time.
Several updated articles on the story are citing officials saying that the stomach and intestinal contents of the bear that was feeding on him are consistent with that bear being the one that attacked. In addition, they have determined that the bear the man was photographing (when he ignored park rules) is the bear that was feeding on him. So, all current evidence points to him being killed by the bear he failed to leave alone.
It wasn't the wrong place at the wrong time. It was the wrong place because he didn't follow the rules he agreed to when he obtained his permit, and leave the area.