Hold your horses right there! If it is a loan there is tax to be paid for Redknapp to claim he didn't know this was the case is a little licentious as he fills out a tax return/should have been informing his accountant of the monies as failure to do so will cause him problems!
The reason the loan is taxable is because it is a benefit in kind from an employer meaning tax equivalent to the value of the interest for the period borrowed for should be paid by Redknapp (hence why Mandaric is trying to claim it is nothing to do with any bonuses Redknapp is owed, a story that is a little thin on the ground when MM was employing HR at the time).
If (and as I think is the case in this instance) the loan wasn't repaid then tax is due on the whole amount. This is tantamount to tax evasion hence there is a wrongdoing and Redknapp needs to be punished accordingly. If you think this is just going to be in the form of a lecture/small fine, I think you are mistaken, it is likely to be a 6 figure fine IMO.