One person was seriously injured PM, a 25 year old female who had to be airlifted to Mackay Hospital with (according to that same newspaper - The Daily Mercury - as quoted above) "head and neck injuries".
Like you've noted though, it's a miracle it wasn't way worse. This accident could have easily eclipsed the South Pacific Seaplanes 185 crash in the Hawkesbury River back in 1998 and become one of the worst GA crashes ever.