The $5M security deposit is pretty clearly the joint responsibility of SCS and Sapetro under PSC 3 amendment (paragraph 4.7 (c)) and the Farm Out Agreement (Section 3.3) and is due 30 days after date of signature of the Presidential Decree (which was April 21, 2017). Thus the security deposit from SCS and Saptero is due by Sunday May 21, 2017.
Additionally the PSC Amendment 3 provides (in paragraph 4.6 (e)) that
"...The Government may terminate the Contract, immediately and without prior notice for failure to comply with section 4.7 (c)."
This is not inconsistent with the other requirement that the "Transaction Documents" be Closed by SCS by May 31. This would include the Closing for the Farm Out Agreement and resulting Deed of Assignment and JOA and Parent Company Guarantees. To make this date under the Farm Out Agreement Hyperdynamics has to provide a Closing Notice 5 days prior to Closing. To provide the closing Notice they have to satisfy the closing conditions (including raising the necessary funding) by a "Trigger Date" 5 days prior to the Closing Notice. Thus they have to obtain financing and meeting other closing conditions in paragraph 2.1 10 days prior to Closing--or May 21.
It is interesting that as of March 31 (date of signing of the Farm Out Agreement) the target date agreed to for all of this by HDYN was April 10. so they must have thought the funding was doable by April 10 at that time, but obviously something happened and we now have 3 weeks to what appears to be the final deadline.