It's only once the true facts (as the relatives see them) have come out, who did what, who didn't do what, that some people can begin to come to terms with grief. It gives a focus for their emotions, as opposed to a blank denial of responsibility from those who are responsible.
Everybody is different, it's relatively easy to say "it's 25 years ago...you should be over this by now" from a distance, but when you're in the midst of that it is, I suspect, a very different position. Grieving the death of a family member or loved one has no timetable, no straight line recovery from the depths of despair to 'normal'. People aren't necessarily wallowing in grief, they be mentally stuck, traumatised, unable to progress with their lives. There is a member of my family extended family who has never recovered from the death of her husband in the very early 1970s, and never will. It's not wallowing in grief, it's an inability to recover.