In the Name of the Grandfather - S20-E14
Corrected entry: Homer and Grandpa apparently buy the pub in a drunken mistake. The previous owner says, "You sure do know a lot about Irish Real Estate Law". However, the episode is set in Northern Ireland and so any laws are those of the UK. He wouldn't make that mistake.
Correction: While Northern Ireland is part of the UK, the laws differ slightly between Northern Ireland, Scotland, England and Wales, so therefore what he said is true.