Okay, John and Mary have never been Catholic, but are baptized Christians. They get married outside the CC (presumably valid in the eyes of the CC, because John and Mary are not Catholic and thus not obligated to follow Catholic rules of marriage). John and Mary then get a civil divorce (NOT recognized by the CC and also not recognized by many Protestants). Mary then marries Bill in a ceremony recognized by some liberal Protestant church as valid (NOT recognized by the CC or by some Protestants because Mary was not free to marry). Time passes. John dies due to natural causes/disease/accident or another reason not intentionally caused by Bill or Mary. What is the situation of Mary and Bill in the eyes of the CC? Mary is now longer bound to John because he is now dead. Does John's death retroactively validate Mary and Bill's 'marriage', or would they have to go through another ceremony to get married 'for real' this time? In a more general sense, if the parties are not free to marry when the ceremony actually takes place, but the situation that was preventing them from being free to marry becomes resolved at some future time after the ceremony is complete and they have begun to cohabit, does that retroactively 'fix' the marriage and make it valid, or does it mean that the marriage is still null, but the parties are free to get married 'for real' if they so choose? If the second, is this the same process as a Convalidation that is used to rectify the situation when a Catholic has gotten married outside the CC, or would it be of a different nature or form?
I'm not talking about whether or not Mary and Bill have sinned in the eyes of the CC, and to what extent, by living together in an invalid marriage. That might depend on their knowledge of the situation and the rules of marriage. What I am interested in is what their standing would be before the CC if, say, they wanted to convert or if they otherwise needed to get the CC's viewpoint of the situation.
While this question is based on people I know, it does not involve me and the people in question are not currently investigating the CC to my knowledge.