The OED doesn't list "not able to catch fire" (or anything like that) as one of the meanings of inflammable.
Merriam-Webster's Dictionary of English Usage says: "We don not know whether [misunderstanding "inflammable" to mean "nonflammable"] has ever actually occurred."
It happens all the time, factoid for example originally meant a false piece of information repeated so often people incorrectly believe it to be true. So many people however believed that a factoid was a brief piece of information that it ended up being a definition in the dictionary, so now factoid can mean either a false or a true piece of info depending on who you ask.
Wikipedia says The company can be recognised by its green crocodile logo. René Lacoste, the company's founder, was nicknamed "the Crocodile" by fans because of his tenacity on the tennis court.
I looked it up, and it's a total of three different blokes. Jón Páll Sigmarsson and Magnús Ver Magnússon won it 4 times each in the 80s & 90s, and Hafþór Júlíus Björnsson (pictured above) won it in 2018.
Alright, it's pedantic, but technically, London has been electing mayors since the 1100s. The phrase you really want there is "What city chose Ken Livingstone as its first directly elected mayor in the year 2000?"
Merriam-Webster's Dictionary of English Usage says: "We don not know whether [misunderstanding "inflammable" to mean "nonflammable"] has ever actually occurred."
One of my best results yet though on these quizzes 19/20! Just missed Odysseus.