My understanding is that those who have sent in their...

My understanding is that those who have sent in their acceptances are locked in to handing their shares over for 70c. The defeating conditions are get out clauses for GEM, not shareholders. GEM of course have said they will not invoke the defeating conditions if they get their 90%. In the meantime though those that have sent their acceptances can not withdraw their offers. That choice rests purely with GEM.
So, if they could buy another 18% on market for say 75c average the remaining 10% could be compulsorily acquired for 70c and all those that have sent acceptances get their 70c. A cheap and sneaky way out.