I have not read the AR so this is purely a guess but...
If he is simply lending the cash with no returns besides the interest being paid by BK and co then its not ownership. However if the owners fail in their repayments ownership is transferred to Green depending on how much coin hes lended to Everton and BK in particular. Much like owning a house I would have thought? I can see how Wyness came to this conclusion as the financial pressures being faced by the club would mean this is always hanging over their heads. That said if this is the case then he is wrong in his statement that Everton can't be sold but with that large debt it doesn't make for an attractive proposition. Also through creative accounting and whatnot it is easy to show that the business is in a better position than it actually is.