Denis O’Brien has a dilemma. In April, he managed to get Digicel’s creditors off the company’s back. After tough negotiations, they agreed a deal which would leave the company in O’Brien’s control, and wipe a quarter off its debt pile. How did he pull it off? A Digicel default would have been one of the biggest in Caribbean commercial history. It would have dragged through the local courts, and the outcome would not have been certain. So creditors wanted to avoid it.  As good a deal as it was, it had a catch: Digicel needed to refinance its debts within…