I know that this happened in the UK, but in America the friend would have at least been charged with manslaughter and (due to the "circumstances") would have either been given probation or been exonerated. That is so that 20 years later the victim's family couldn't try to charge him with murder. Considering that a good portion of our legal systems mirror each other, it's sort of odd that the friend wasn't at least taken into custody, even as a formality.