Jim,
It was certainly, according to the video, some of the largest hail i've seen in Oz, but the storm that I remember from 1983 or 84 that hit Croydon, and parts of Mooroolbark, Mt Evelyn and Montrose VIC, the hail may have been slightly smaller, but hit with more verocity and speed than this storm - my biggest problem has been trying to find any data (video or written) of this event - I know the storm lasted 45 mins, and intensity of the hail almost broke windows at the school I was in.
But I will still say, this video may well contain the largest recorded stones dropped in the southern hemisphere.
Big Pete