he did have unusual hands. he was described as having small, fleshy fingers, but he could reach an 11th (fullchords too) with both hands, he could reach something like B-E-A-C-E in his left, and he reflected that in his works.
here is an interesting tidbit of info: the theme from rachmaninoff's famous c sharp minor prelude comes from henselt's piano concerto. specifically, it comes from the descending octave grace notes in the entrance of the piano. its not just something i noticed and noted, but it is mentioned in hyperion's booklet for this concerto.