On their faq they say:
Jumbo Ticket is a secured and certified site which is probably fair. Jumbo Ticket strives for 100% customer satisfaction.
But we can't find any certification link on the site.
Great point. I think Jumbo Ticket must consider being fair and transparent in every steps. I would also recommend this and along with this, also, picking the winner should be transparent in a way which can be verified by anyone through online.
Anything that cant really be verified wont really be totally considered to be fair even if they do really make out some mentions about being provably fair but if it wasnt proven then it would really be just good
as verbal which we know that this is something wont really be giving any attention and might end up likely on getting ignored if they wont really be putting importance on what the community is been asking.
Lottery results should be transparent as much as possible because this is where people are really that keen when it comes to that.