According to today's Melbourne Age, 'uncopyrightable' is the only 15-letter word in English that can be written without repeating a letter. Are they right?

do they mean to imply that it is the longest such word in English?

I dunno, tsuwm, I just copied the statement as it was printed [as a 'nafffact']

well, according to The Old Farmer's Almanac (I'm just Old, so can't vouch for accuracy) The longest word you can spell without repeating a letter: uncopyrightable

here's some more verbal trumpery from the same source, which we can use perhaps to judge the veracity of same...
The longest word with just one vowel: strengths
The only English word with a triple letter: goddessship
The word with the longest definition in most dictionaries: set
The shortest "ology" (study of) word: oology (the study of birds' eggs)
The only word in which an "f" is pronounced like a "v": of

hmm, interesting source, the OFA -- only a few days ago the "nafffact" was about 'oology', so we might look forward to others from the same source, which they don't acknowledge of course.