All lotteries around the world have ruling in case there is a dispute on the ticket , it is clearly stated that
“The National Lottery Rules for Scratchcard Games make clear that only one person can be the owner of a ticket and that only the person whose name and address is written on the back of a winning scratchcard can claim a prize.
“This means that a prize can only be paid to one person and this is always communicated clearly to prize claimants.
So whatever agreement they have about the winning it should be on paper and the holder of the tickets gets to decide whom she will share his prize on this case it looks like they do not have a very strong relationship that when an issue like this comes up they have a disagreement the man has a case because the money that was used to purchase the ticket comes from his pocket but she can claim that the money was a loan for her to buy the ticket.
I don't think it will stand in any court where the lender of the money that was used to purchase for the winning ticket has the right to the winning ticket.
if the court will rule in his favor then any employer will ask his employee that won millions in a lottery to share his winning because the money comes from his
pocket, the rule is who bought the ticket whose name is written in the back deserves the prize regardless of where the money comes from.
There was similar scenario that made headline where a man give his friend a set of numbers to bet and it happens that the winning set of number hit the jackpot, and the giver is asking a 50% share, the court denied his claim because, the winner is the one who decided to bought the ticket, his name was behind the back of the ticket, regardless if there 's someone who gave the winning numbers.