I don't know too much about annulments. Is this "defender of the bond" something new? The few people I know who've gotten annulments never mentioned anyone who was defending their marriage. And a friend of my wife's received an annulment although she'd been married for many years and had five children. (Husband had a girlfriend, of course). This woman very strongly believes her annulment is not valid in the eyes of God, but we don't recall her ever mentioning that the diocese had somebody helping her defend her marriage.
Defense of marriage ping.
Its a simple straightforward process the goal of which is to respect (or defer to) a marriage that has/had the appearance of legitimacy.
Money is not the key - as the disgruntled or cynical often complain.
Sadly, those with power often get the annulment they want - but often those with no power also get the annulment they want.
The other ridiculous and tired canard is that the children of an annulled bond are made illegitimate as a result of the annullment - which is not true.
Marriage is gravely serious, lifelong, and sacramental. To treat it otherwise is to mock the most solemn vows.
Nope. The Defender has been around since at least the first Code of Canon Law was issued, in 1917. He doesn't actually work with the respondent to "get another side" of the case. In fact, the Defender has no contact with the parties at all. He examines the final case, with all the witness testimony, and raises objections to an annulment (such as: length of time married, no obvious difficulties until recently). However, given the psychological grounds which form the basis for 99% of the cases presented, it is very difficult to argue length of time married if the husband was a lifelong alcoholic, for instance.
The court of second instance will usually look very hard at the Defender's case. (I was a Defender in a couple of cases, and had to write up a case just as the Procurator did).