I actually have to say I think the whole thing was rather well done. I loved the Faure music to go with it (the same piece of music to which the magnificent Inspector Morse died), and I even thought, in his dying moments (so to speak) that Mark's acting improved. He was really quite manic when he announced that he'd made his decision ... and Natasha was wonderful with her calm, "You don't get to make decisions anymore", Bang!
Certainly I can see why the rest of the family (both sides) are so upset; it's certainly mucked up their lives, at least for a while ... but there is a bit of me that says I wish Natasha had made the hole a bit bigger whilst she was digging - could have got the egregious Sally in there as well; and killed two birds with one stone!