Ann: Trading Halt, page-285

"We are only in a TH because it's a joint announcement between two different parties"
What a load of rubbish. The other party is not connected to the ASX so has no part in the TH.
There could have been discussions between the two parties whether to make an announcement or not.
If the update is to announce that they are now testing and all is well then I do not see it as requiring a TH. I do not think that an announcement like a technical update without a TH would cause such a huge rise in the SP.
If the ASX was informed that there could be a jump in the SP then the ASX would be aware and allow normal trading. If the ASX do not know then they will suspend trading but as the TH was put in place by the BOD then I think we may see the return of PL2 scenario and they are looking as to why things have turned bad.
In my opinion only.