In this scenario, you will know when the shorting is covered and the buy back begins. That is also when you will know when the deal has been signed, IF it gets signed.
Since we're speculating, could be a possibility that there is an agreement already signed and post dated to May 7. This gives Siam time to manipulate price with the Dr's borrowed shares in order to own most of ACMG and ACMG licensing company. Every share they shake lose from investors is another piece of the company they own. Every share traded after March won't get the dividend so it is in their pocket and in their favor to scoop up as much as they can before this thing rockets North.