Having just visited the affected areas and witnessed the damage, I would have to say there is not a lot of doubt that it was a tornado. I was (as always) very sceptical when I drove up to Rockingham to do a damage assessment, as a large percentage of reported tornadoes see me end up looking at typical straight line wind / microburst damage. However, having spoken to a handful of witnesses and viewed the area I have no doubt that the event was quite significant. As to putting an F on it, well I suppose it was F2 given that whole roofs were destroyed, of course there is always the contentious "How well built was it", but working with what we have I would be confident in saying F2. I believe that there is some footage being kicked around at present?? Haven't seen it yet myself, having spent most of the day driving and a relatively small percentage of it actually taking pictures and interviewing people. (Officially, not rubbernecking!!)
For anyone interested I would recommend the following - "The Cool-Season Tornadoes of California and Southern Australia" (Hanstrum et al - That being ourvery own Barry Hanstrum of the BOM) which can be found in pdf format at a couple of sites on the web.
Can't recall if I have posted a Link previously?? - Getting old See!!
Best regards
Kris