Home leave for prisoners coming near to the end of a long sentence has been standard practice for many years. It only applies to prisoners who are in 'open' prisons and is to help them readjust to the outside world. It has been very successful and there have been very few absconders.
This man like all 'lifers' would only be released on 'licence' they can be recalled to prison at any time. He has also blown his chance of release now as when he is captured he will be returned to a 'closed' jail and have several more years to serve before he will be considered for parole again.
Only prisoners who have less than a year left to serve can get home leave. They are never escorted as that would make the release pointless. In addition to that there is a severe shortage of prison officers so non can be spared to escort a home visit.
The usual reason a prisoner absconds is that they have got into debt to the prison drug barons and they fear for their safety. They would be stupid to throw away the chance of freedom in just a few months. Once caught this prisoner will relocated to a prison many miles away from the one he absconded from. This is not an 'escape' as he was released to go on home leave , it counts as absconding not as escape.