I believe it to be certain that HIG will use the $15M to buyback...

I believe it to be certain that HIG will use the $15M to buyback portion from Cobalt27, and that this is clearly expected by both.
Reason for the complication of the arrangement, including that it is at HIG's option for a limited but sufficient period of time ( I believe ) is that there are legal or listing rules/issues related to the issue of new shares representing of 15% of company that would prevent the money then being compulsorily paid back to Cobalt27 (and that HIG needed to establish a real price for the issue) - some lawyer may want to give a better explanation.