The official website of Guinness World Records confirms the claim.
Recalling the incident in 1954, he thought of creating a company helping to settle such arguments in drinking bars. So he invited the twin brothers Ross McWhirter and Norris McWhirter, who were fact-finding researchers from London, to compile a book of facts and figures from across the world. Work on the book started in two rooms of a converted gymnasium in London which went on to become a globally-recognized brand trusted for world records.
Thus, the Guinness Book of Records was initially started out as an idea for a book of facts to solve arguments in pubs.