Were it I facing your situation I would (If the 1099R is truly in the name of the estate, and the $ got to the beneficiaries)

Offer to amend the 2024 1041, to correctly show the distributions and income to the beneficiaries, and the income distribution deduction on the 1041.

If the answer to the above is they don't wish to change it, I would hand him back his paperwork and wish him luck.

I would also inform him that the prior 1041's are likely incorrect and they and the personal returns should theoretically be amended as well.