He owns 33,932 shares after selling 100 shares at $58 on the 20th Feb. For context, actual directors hold about 3m shares/options between them I think. I wouldn't stress about the COO selling 100 shares - or if he sells even more than that tbh.
Maybe a little concerning is the ASX CDI conversions becoming available for disposal on the market this week and holders using the Computershare sale facility, where they have less control of the timing of the sale. The stock is thinly traded with low volumes at the mo so small amounts can shift the price easily. If C/share sell (or dump) a bunch at once, "at market" then this might explain the price movements from the last 2 nights. Seems the easiest and quickest way to dispose tho.
SZL Price at posting:
$24.35 Sentiment: Buy Disclosure: Held