So right, this is not a matter of halacha that we are discussing here it is a matter of an emotional nature and human nature. It is irrelevant that the Kesubah is invalid, would he marry her again then with a new kesubah? The kesubah issue can be easily rectified.
The question is would he not feel betrayed? Would he just continue business as usual or would he say the kesubah is invalid and you are no longer my wife!