I was at the same meeting, but over by the hairpin at the time. We were stunned! He was riding a local TR500 Suzuki running on methanol. Getting in his hand before taking up a Suzuki works ride. Not Geoff Perry's.
Interestingly, a guy I worked with here in Perth, was at the same meeting (he also rode a TR500 Suzuki). He reckoned that Cal's mechanic adjusted the carbs, just before the race, but inadvertently leaned them out, as he would have on the Harley, instead of making it a bit richer. Lack of experience with 2 strokes?? The bike seized at speed.........!