Brig Oubridge, owner of a two-and-a-half site in a valley between Cwmdu and Abergorlech, appealed after both William Hague, the then Welsh secretary and Alun Michael, head of the new national assembly, overruled a public inquiry's decision to approve three tepees as well as a caravan in 1995.
Mr Hague and Mr Michael approved only the caravan, but the high court was shown a photogragh taken in 1983 by an enforcement officer from Dinefwr BC, now part of Carmathenshire CC, showing a tipi alongside the caravan.
Under planning law any unauthorised development qualifies for retrospective planning consent if it has existed for ten years or more.
'It suddenly appeared from the council's folder under questioning from my barrister.
'The judge said on Wednesday after hearing one day of submissions that he was minded to refer the matter to the national assembly on the grounds that two secretaries of state had disregarded the importance of that photograpgh.'
John Litton, defending the national assembly, said Mr Michael had wrongly disregarded evidence proving the existence of tepees ten years before the day of the planning application.
The matter may now be referred to the assembly's new planning panel for fresh consideration.