Answer:
Whoever administers Mr. Simpson's estate is responsible for filing his final tax returns. Mrs. Simpson is no longer responsible for Mr. Simpson's tax filings, they divorced 2 years before Mr. Simpson died. Mrs. Simpson is not including in her tax filings any of Mr. Simpson's income, deductions, etc., so she is considered a separate entity. The person in charge of administering Mr. Simpson's estate, it might even be Mrs. Simpson, must file Mr. Simpson's final tax returns. Not even death saves you from paying taxes.
