Are there any papers out there that describe why loan recovery rates > bond recovery rates where the bond/loans exhibit the same collateralisation/subordination

Credit is not my strongest suit and I have no papers to suggest to you, but I'll just throw out something off the top of my head. Loans are more likely to be closely held than bonds and hence loan owners are more likely to be better organized at protecting their economic and legal interests than a more diverse set of bond holders. Lenders are generally closer to the client than bondholders and they arguably might even be more sophisticated. They may also have more levers available to pressure the borrower. As an example, a lender might also have other deals/products with the borrower (e.g. a current account) and can hence cause the borrower more problems if things go potty.

yes this is the common persception although i needed a reference on it.

also, re-organizing a business (instead of liquidating it) requires investing new money in it ... Apart from converting existing bonds into equity, you're not going to be able to raise money in the capital markets, you'll have to borrow it. The best loans are probably from people who already have loaned you money. Many reasons for this; some benign and some less so.