Journalists are lazy on this; they don't specify to whom the debt is owed.
If you own a club then the most tax-efficient way of putting money into it to cover losses is as debt; because should the club ever have money that you can take out then you just repay your own debt. There's no tax on it; unlike a dividend payment or a salary.
Unless these debts are owed to a third party then they're only technically debts. In reality they're historic accumulated losses that the owner has funded with his own money.
Hence the Bolton owner writing off £180m of "debt", Steve Lansdown converting his " debt" to equity (which means accepting that he's not getting it back), and Nick Higgs demanding that all of his "debt" gets repaid if there's a sale.
Spot the odd one out.