They didn't. The process in this sort of case is ASX sends a "please explain" letter. Unless the company is in a position to respond immediately (unlikely) the risk of continuing to trade is too great if the ASX's query is suggesting a breach of the Listing Rules (usually LR 3.1). So the company really has no option other than to request a TH.
The initial ASX letter containing the query is often not released to the market until the company's answer has been submitted - i.e. a couple of trading days later.
The conduct of the ASX reminds me of the old maxim that all decisions are personal decisions. Someone at the ASX, possibly more senior than Mr Secrett, has got themselves miffed at AVZ and is imo acting petulantly. We will see - maybe I'm wrong and the query will disclose genuinely dastardly conduct by the company (but I very much doubt it).
AVZ Price at posting:
22.5¢ Sentiment: Buy Disclosure: Held