If one is to be absolutely strict and literal about what Jesus said on divorce and remarriage, as the question was about a preacher that not only divorced but also remarried, looking at Jesus' words, though he allows that divorce under the one justification is permissible, he does not go on to say that remarriage is. He calls remarriage adultery without any qualifying statement exempting those that have divorced for legitimate reasons. Now that could be an oversight on His part or he may think it was clear enough from the context or He could mean no one that is divorced, whatever the justification for that divorce, ought to get remarried. I surely won't try to read Jesus' mind on that. The OP also seems to me to be asking a philosophical question for individuals not so much seeking the position of any church body or denomination. The OP may even already know what the several hierarchical structures have proclaimed but want the opinion of individual laypersons.