Also i dont see how Manchester United can operate half a billion pounds in debt and not get issued winding up orders by HMRC, if we were 500million pounds in debt we would get wound up in seconds!
For a start, I don't know whether Manchester United have any debts to the Inland Revenue. I thought most of their debt was to the banks? HMRC will only issue a winding up order to a company that owes them money.
Second, with regard to the debt levels, it depends on their ability to pay the interest. Our income wouldn't come close to covering these payments but Manchester United won't face any problems (by that I mean winding up orders) unless they start missing payments.
This might become more likely if Portsmouth hit the wall. All of a sudden, investing in a Premier League club becomes a much riskier investment and so investors are going to require a higher return (i.e. higher interest).