Can we kill this issue?
The spin by the losing applicant is that the result could have been declared void if it had been a binding referendum but couldn't be because it was only advisory.
While the court said that "An advisory referendum is a very different animal from a binding election" it would not necessarily have allowed that the corrupt overspending meant the result should have been void. First, you'd have to show that 600,000 would have voted Remain rather than Leave (*) to affect the result and second, the Act to have the referendum made no provision for overspending breaches so you'd have to prove a "common law" right to apply other legislation. The judges didn't think either case was proved. * If my maths is right there's a mistake in how that was argued based on the number of facebook users who were targeted by the illegal overspending but that makes little difference to the case.
The only real comfort I can see for the Remain case is you can kill the claim that the referendum was binding (it was only ever advisory in law) and a little obiter about the political aspect - the court said they were not going to "enter a political arena to determine questions well outside its proper remit" (though that hasn't stopped judges making political judgements) but there was still a little hint as to whether it was still a good idea to leave: "The referendum was merely advisory; and it was up to those that it advised to consider whether, in all the circumstances, the EU referendum result was and continues to be sufficiently robust as to reflect the will of the people on the question of withdrawal from the EU".
https://www.bailii.org/ew/cases/EWCA/Civ/2019/304.html