I agree with Jamie. There's nothing to suggest anything other than Morelia spilota mcdowelli.
It's always a good idea to see photos of the parents, especially if you're ever in doubt but there's almost no way of knowing if a Morelia spilota (or any specimen really) is 100% pure these days when buying. There's always a certain amount of trust involved. The better you know the seller the better and it's best to buy from someone with a good reputation.