Good points, twf. I can understand how they must be feeling. You and I understand the 3 things necessary to make a sin mortal, particularly the “lack of knowledge.”
I have thought long and hard about this myself … let’s say a couple are the type that BXVI was concerned about – baptized ‘pagans’ who use the Church to have a ‘nice’ wedding, with no real concept of faith in the sacrament. The marriage fails and the abandoned spouse eventually remarries, say 20-25 years later – but not before applying for an annulment. Due to the time lapse, lack of witnesses, etc., the tribunal has little to go on other than the petitioner’s word that he/she did not have a proper sense of marriage at the time of the pretty ceremony, which was more for show and parental approval than real faith. '
Good’ Catholics get married in church, yes?
This person’s conscience was formed after much prayer and certainty before God, they believe that their first marriage was invalid, though no annulment was granted; is this person to go through the rest of their life without the sacraments? Is God THAT unmerciful? St. Paul tells us “remain in the state you were called” … meaning, when God called you to Himself as a slave, remain a slave. [Cor. 7:21-24] If 25 years later, God’s love is calling this repentant person to Himself, but no recourse may be had to an annulment, what then?
In certain case by case scenarios such as this, I truly believe it would not be wrong for them to receive the sacrament, since the 3 conditions for mortal sin are not present. IOW, it is NOT adultery. Remember, Kasper said repeatedly that this is not blanket approval, but a
case by case matter to be decided between the confessor and the penitent. I would hope that some type of guidance comes from the Synod that would help these pastors. It seems utterly deplorable to me that Burke would thwart this process due to fears of what may come forth. It desperately needs to proceed as Francis directed. May God move us to earnestly pray for God’s holy will to be done as He guides the participants.

Please know that I am so devoted to the Church that whatever is decided is ok with me, and I will rejoice in the final decision.