The mistake they made is to directly say "one of the first countries" in the article title, which immediately implies a comparison to foreign countries. But clearly, since they're talking about England, which is a subdivision of the UK, why aren't they comparing this achievement to equivalent subdivisions, such as states or provinces, in other nations instead? This isn't a direct comparison (which might also make it an unfair one), so it makes sense why people would misread them by assuming that this is an error and that they meant to compare equivalents.