You cannot judge anything really by looking at the "Market Depth" when a stock is in a Trading Halt. The ASX scatters random Bids & Offers with Offer prices lower than Bid prices deliberately to highlight suspended trading.
About the only possible guide, at any particular time, is an "Indicative Opening Price" which can & does change frequently up until the second that the stock recommences trading.
SDA's current Indicative opening price at this very point is ...
SDA Price at posting:
79.0¢ Sentiment: Hold Disclosure: Held