If the "donor" had a licence, even an expired licence, and you have the details, you could ask the "donor" to explain to the wildlife people that he/she had lost interest in the snake, let the licence lapse, but he/she passed the snake onto you for want of knowing what else to do. People lose interest all the time, and many don't tie up the loose ends with the Departments when their licences expire. All departments are under resourced, so don't have time to follow up on every lapse. If you approach them, preferably in tandem with the person you got the snake from, it saves them the time following up on a lapsed licence, and should resolve the issue with your recent acquisition. It would be far easier for them to terminate a licence and re-permit the animal to you than go through a process of punishing. People lose interest all the time and just disappear off the radar - it doesn't make their jobs easy but it's not a hanging offence, and it would be better for you to make the approach openly rather than wait for them to follow you or your "donor" up.
Kingofnobbys wrote an alternative strategy while I was writing mine - his might be a better approach actually - if you have the details (licence number etc) of the person who gave you the snake, just enter it as normal into your record book - it really isn't your problem if the permit had expired, and it would be highly unlikely that they'd bother to confiscate your snake anyway if it's now legit and in good hands.
As mentioned recently in a few threads here, snakes don't need UV by the way.
Jamie