Firstly, this is a very sad story.
Having said that, if you look up other articles on the story (eg
http://www.news.com.au/story/0,23599,24133445-2,00.html), the problem was that the woman had no interest in bondage, and her husband talked her into tying him up. Pretty much the same as if a husband forces his wife to go hunting with him, even though she has no idea how to use a firearm, and she ends up accidentally shooting him.
The other bad part of it (aside from the obvious tragedy) is that this is the sort of story that makes people who know I'm into S&M say things like 'I'm worried about you - don't people DIE doing that?"