The re-registration passed without much public comment, and the issue of his gender would remain a private one until 1965. That December, his elder brother died, leaving daughters but no sons, and thus posing a problem of inheritance. The barony could be inherited by heirs male or female, and so passed directly to Sempill's eldest daughter
Ann, but the baronetcy – along with the bulk of the land – would have to pass to the first male heir. The family had assumed that Ewan would inherit, as the younger brother. Following the death of the Lord Sempill in December 1965,
The Times cited ''
Debrett's'' in reporting that the heir to the baronetcy was the Hon. Ewan Forbes-Sempill, "formerly registered as Elizabeth". However, this was challenged by his cousin John Forbes-Sempill, who argued that the 1952 re-registration was invalid. This would mean that Forbes was still legally considered a woman, unable to inherit the title, and so it would pass to John Forbes-Sempill. A total of twelve medical experts were called to give evidence. Professor
Louis Gooren returned to his records of the case in 1999 and "concluded, with hindsight, that Forbes-Sempill was almost certainly a female-to-male transsexual"; the details that have since emerged of his treatment make it clear that he was a
trans man. The judge's ruling was that "as a matter of probability, the second petitioner [Ewan Forbes-Sempill] is a ... hermaphrodite", according with the legal requirement of "indeterminate at birth". It has been suggested that the judge desired to ensure the estate and the title was inherited by the "right" candidate, and was flexible with his judgement to obtain this result. The ruling continued to be challenged by John Forbes-Sempill, who caused it to be referred to the
Home Secretary,
James Callaghan, as the person responsible for the
Roll of the Baronetage. Callaghan consulted the
Lord Advocate, and finally declared in December 1968 that Ewan should be entered on the Roll as the rightful holder of the title. The level of secrecy of the case, which was criticised by some contemporary observers, meant that it was not properly recorded or published, and the exact facts of the argument were not known for some time. As a result, whilst it sharply differs from later rulings such as
Corbett v Corbett (1970), it was not able to be considered as
precedent in later judgments on the
legal recognition of gender variance. However, further release of records was limited, with the Lord Advocate's office stating that disclosing the files "would not be appropriate", and the case would not be fully publicly documented until 2021. ==Later life==