The gemarah has a machlokas whether a chalul whose kohain father died within 30 days has to redeem himself. The reason for the view that he's putter is because he's coming from someone (the father kohain) who other kohanim couldn't take the 5 slayim from him.
this logic seems faulty. Since the father died before there was any obligation to redeem him. Hence the only obligation was on the son who's a challul, and he has no right to keep it for himself (like his father would)
maybe a possible answer is that when he son was born, all the other kohanim was Miyayish (gave up hope of ever getting the money). therefore, when the father died the money became "hefker" and the kid is allowed to keep it
Even though the obligation was not in this world when the father died (davar shelo bo laolam). But the gemarah in gitin 30A gives an ex. of yi'ush by something that didn't grow yet.

This message has been edited. Last edited by: Rav Chaim,