If PD got his money back would that definitely result in new ownership?

PD, by some mechanism almost certainly involving AJ, forces the full £2.7+ million debt repayment. Then PD entirely walks away, leaving The Three and CUOSC in their Holdings board positions and with all of their equity.

At that point the only significant debt of 1921 would be to Pioneer, which would be somewhat amusing to PD. Of course the ongoing inept running of the club would continue and none of Cumbria's biggest / best businesses would contribute sponsorship / advertising / free goods and services etc. So the decline would begin again with the debt to Pioneer remaining.