Causing the Loss to Who?

Rav Kahana and Rav Assi asked Rav (Kesuvos 89b): According to you, who maintains that if the woman produces her get, she would collect the primary amount for her kesuvah (even without producing her kesuvah), with what evidence, may a woman, widowed from nisuin, offer in order to collect her kesuvah? The answer is obvious: She brings witnesses that her husband died! However, the question may be raised, let us be concerned that she was previously divorced, and later, she will produce the get and collect the primary amount of her kesuvah with it (since Rav is of the opinion that we do not write a receipt for the inheritors)?

Rav answers: She may collect her kesuvah only if we know that she was living with her husband until he died (and there was no divorce).

They asked: But perhaps, he divorced her right before he died?

Rav replied: If that was the case, he has caused the loss upon himself.

Reb Elchonon Wasserman in Koveitz Shiurim (319) asks: Why would the inheritors be obligated to give her the kesuvah in this case; the father is not causing the loss to himself; he is causing a loss to his heirs, who will now be responsible to pay her for the kesuvah?